U.S. patent application number 14/766298 was filed with the patent office on 2015-12-24 for organic compound and organic light-emitting device.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Koichi Ishige, Ryuji Ishii, Takayuki Ito, Norifumi Kajimoto, Jun Kamatani, Nobutaka Mizuno, Masanori Muratsubaki, Yosuke Nishide, Akihito Saitoh, Naoki Yamada.
Application Number | 20150372238 14/766298 |
Document ID | / |
Family ID | 51658495 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150372238 |
Kind Code |
A1 |
Yamada; Naoki ; et
al. |
December 24, 2015 |
ORGANIC COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE
Abstract
Provided is an organic light-emitting device capable of
outputting light with high efficiency and high luminance. The
organic light-emitting device includes an anode, a cathode, an
emission layer placed between the anode and the cathode, and an
organic compound layer placed between the anode and the emission
layer, in which the organic compound layer contains the following
compound A and compound B: [Compound A] an organic compound free of
a nitrogen atom and a metal atom, the compound having SP.sup.2
carbon atoms and SP.sup.3 carbon atoms, and having a ratio of the
number of the SP.sup.3 carbon atoms to the number of the SP.sup.2
carbon atoms of 40% or more; and [Compound B] a compound having a
tertiary amine structure.
Inventors: |
Yamada; Naoki; (Inagi-shi,
JP) ; Kamatani; Jun; (Tokyo, JP) ; Saitoh;
Akihito; (Gotemba-shi, JP) ; Nishide; Yosuke;
(Kawasaki-shi, JP) ; Muratsubaki; Masanori;
(Tokyo, JP) ; Ishii; Ryuji; (Yokohama-shi, JP)
; Ishige; Koichi; (Yokohama-shi, JP) ; Ito;
Takayuki; (Kawasaki-shi, JP) ; Kajimoto;
Norifumi; (Tokyo, JP) ; Mizuno; Nobutaka;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
51658495 |
Appl. No.: |
14/766298 |
Filed: |
April 3, 2014 |
PCT Filed: |
April 3, 2014 |
PCT NO: |
PCT/JP2014/060350 |
371 Date: |
August 6, 2015 |
Current U.S.
Class: |
568/632 ; 257/40;
315/200R; 345/173; 399/220; 585/27 |
Current CPC
Class: |
C07C 25/22 20130101;
C07C 2601/14 20170501; C07C 2603/26 20170501; C07C 2603/40
20170501; H01L 51/0074 20130101; C07C 2603/48 20170501; H01L 51/006
20130101; H01L 27/3248 20130101; C07C 2603/74 20170501; H01L
51/0058 20130101; C07C 13/567 20130101; H01L 51/0072 20130101; C07C
2603/42 20170501; H01L 51/0085 20130101; H01L 51/0059 20130101;
G06F 3/0412 20130101; C07C 13/66 20130101; H01L 51/0054 20130101;
C07C 2603/50 20170501; H01L 51/5012 20130101; C07C 2603/18
20170501; H01L 51/0052 20130101; H01L 51/0055 20130101; G03G
15/04063 20130101; C07C 22/08 20130101; H05B 45/60 20200101; H01L
51/5056 20130101; C07C 13/615 20130101; C07C 43/275 20130101 |
International
Class: |
H01L 51/00 20060101
H01L051/00; H05B 33/08 20060101 H05B033/08; C07C 13/567 20060101
C07C013/567; G06F 3/041 20060101 G06F003/041; C07C 43/275 20060101
C07C043/275; C07C 13/615 20060101 C07C013/615; C07C 13/66 20060101
C07C013/66; G03G 15/04 20060101 G03G015/04; H01L 27/32 20060101
H01L027/32 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2013 |
JP |
2013-077439 |
Apr 2, 2014 |
JP |
2014-076287 |
Claims
1. An organic light-emitting device, comprising: an anode; a
cathode; an emission layer placed between the anode and the
cathode; and an organic compound layer placed between the anode and
the emission layer, wherein the organic compound layer contains the
following compound A and compound B: [Compound A] an organic
compound free of a nitrogen atom and a metal atom, the compound
having SP.sup.2 carbon atoms and SP.sup.3 carbon atoms, and having
a ratio of the number of the SP.sup.3 carbon atoms to the number of
the SP.sup.2 carbon atoms of 40% or more; and [Compound B] a
compound having a tertiary amine structure, wherein the compound A
comprises a compound represented by one of the following general
formulae [1] and [2]: Z.sub.1 Ar.sub.1).sub.n [1]
Ar.sub.2--Ar.sub.3 [2] wherein, in the general formula [1], Z.sub.1
represents an oxygen atom or a phenyl group that may have a
fluorine atom or an alkyl group, wherein, in the general formula
[1], Ar.sub.1 represents an aryl group or an aliphatic condensed
polycyclic group, and a substituent represented by Ar.sub.1 may
further have an alkyl group, an alkoxy group, or a halogen atom,
wherein, in the general formula [1], n represents an integer from 1
to 6, provided that when Z.sub.1 represents an oxygen atom, n
represents 2, and when n represents 2 or more, structures
Ar.sub.1's in parentheses may be identical to or different from
each other, and wherein, in the general formula [2], Ar.sub.2 and
Ar.sub.3 each represent an aryl group or an aliphatic condensed
polycyclic group, and substituents represented by Ar.sub.2 and
Ar.sub.3 may each further have an alkyl group, an alkoxy group, or
a halogen atom, and Ar.sub.2 and Ar.sub.3 may be identical to or
different from each other.
2. (canceled)
3. An organic light-emitting device according to claim 1, wherein:
the Ar.sub.1 in the general formula [1] represents a phenyl group
having an alkyl group, a fluorenyl group having an alkyl group, a
biphenyl group having an alkyl group, or a naphthyl group having an
alkyl group; and the Ar.sub.2 and Ar.sub.3 in the general formula
[2] each represent a phenyl group having an alkyl group, a
fluorenyl group having an alkyl group, a biphenyl group having an
alkyl group, or a naphthyl group having an alkyl group.
4. (canceled)
5. An organic light-emitting device according to claim 1, wherein
the ratio of the number of the SP.sup.3 carbon atoms of the
compound A to the number of the SP.sup.2 carbon atoms of the
compound A is 80% or more.
6. An organic light-emitting device according to claim 1, wherein a
ratio of the compound B in the organic compound layer with
reference to a total of the compound A and the compound B is from
10 wt % to 90 wt %.
7. An organic light-emitting device according to claim 1, wherein a
ratio of the compound B in the organic compound layer with
reference to a total of the compound A and the compound B is from
20 wt % to 70 wt %.
8. An organic compound, comprising a compound represented by one of
the following general formulae [3] and [4]: ##STR00083## wherein,
in the general formula [3], Z.sub.2 represents a naphthyl group, a
fluorenyl group, a phenanthryl group, a triphenylenyl group, an
aliphatic condensed polycyclic group, a carbon atom, or an oxygen
atom, and a substituent represented by Z.sub.2 may further have an
alkyl group, an alkoxy group, an aryl group, or a halogen atom,
wherein, in the general formula [3], R.sub.1 to R.sub.9 each
represent a hydrogen atom, an alkyl group, an alkoxy group, or a
halogen atom, provided that at least two of substituents
represented by R.sub.1 to R.sub.9 comprise alkyl groups, wherein,
in the general formula [3], m represents an integer of from 1 to 6,
provided that when Z.sub.2 represents a carbon atom, m represents
an integer of from 1 to 4, and when Z.sub.2 represents an oxygen
atom, m represents 1 or 2, and when m represents 2 or more,
structures in parentheses may be identical to or different from
each other, and wherein, in the general formula [4], R.sub.11 to
R.sub.28 each represent a hydrogen atom, an alkyl group, an alkoxy
group, or a halogen atom, provided that at least two of
substituents represented by R.sub.11 to R.sub.28 comprise alkyl
groups.
9. An organic compound according to claim 8, wherein the Z.sub.2
represents an aliphatic condensed polycyclic group, carbon atom, or
oxygen atom that may further have an alkyl group, an alkoxy group,
an aryl group, or a halogen atom.
10. An organic compound according to claim 8, wherein the compound
comprises a compound represented by one of the following general
formula [5] and the following general formula [6]: ##STR00084##
wherein, in the general formula [5], Z.sub.11 represents a naphthyl
group, a fluorenyl group, a phenanthryl group, a triphenylenyl
group, an aliphatic condensed polycyclic group, a carbon atom, or
an oxygen atom, and a substituent represented by Z.sub.n may
further have an alkyl group, an alkoxy group, an aryl group, or a
halogen atom, wherein, in the general formula [5], R.sub.2,
R.sub.6, R.sub.8, and R.sub.9 each represent an alkyl group or an
alkoxy group, and may be identical to or different from one
another, wherein, in the general formula [5], m represents an
integer of from 1 to 6, provided that when Z.sub.11 represents a
carbon atom, m represents an integer of from 1 to 4, and when
Z.sub.11 represents an oxygen atom, m represents 1 or 2, and when m
represents 2 or more, structures in parentheses may be identical to
or different from each other, and wherein, in the general formula
[6], R.sub.12, R.sub.16, R.sub.18, R.sub.19, R.sub.21, R.sub.24,
R.sub.27, and R.sub.28 each represent an alkyl group or an alkoxy
group, and may be identical to or different from one another.
11. An organic compound according to claim 10, wherein the Z.sub.11
represents an aliphatic condensed polycyclic group, carbon atom, or
oxygen atom that may further have an alkyl group, an alkoxy group,
an aryl group, or a halogen atom.
12. An organic compound according to claim 8, wherein the compound
has SP.sup.2 carbon atoms and SP.sup.3 carbon atoms, and has a
ratio of the number of the SP.sup.3 carbon atoms to the number of
the SP.sup.2 carbon atoms of 40% or more.
13. An organic light-emitting device, comprising: an anode; a
cathode; an emission layer placed between the anode and the
cathode; and an organic compound layer placed between the anode and
the emission layer, wherein the organic compound layer contains the
organic compound according to claim 8.
14. An organic light-emitting device according to claim 13, wherein
the organic compound layer further contains a compound having a
tertiary amine structure.
15. An organic light-emitting device, comprising: an anode; a
cathode; an emission layer placed between the anode and the
cathode; and an organic compound layer placed between the cathode
and the emission layer, wherein the organic compound layer contains
the organic compound according to claim 8.
16. An organic light-emitting device, comprising: an anode; a
cathode; and an emission layer placed between the anode and the
cathode, wherein the emission layer contains the organic compound
according to claim 8.
17. A display apparatus, comprising multiple pixels, wherein at
least one of the multiple pixels includes the organic
light-emitting device according to claim 1, and an active device
connected to the organic light-emitting device.
18. An image information processing apparatus, comprising: an input
portion for inputting image information; and a display portion for
displaying an image, wherein the display portion comprises the
display apparatus according to claim 17.
19. A lighting apparatus, comprising: the organic light-emitting
device according to claim 1; and an AC/DC converter circuit for
supplying a driving voltage to the organic light-emitting
device.
20. An image-forming apparatus, comprising: a photosensitive
member; a charging portion for charging a surface of the
photosensitive member; an exposure portion for exposing the
photosensitive member; and a developing unit for developing an
electrostatic latent image formed on the surface of the
photosensitive member, wherein the exposure portion includes the
organic light-emitting device according to claim 1.
21. An exposure machine, comprising a light-emitting member, the
exposure machine being configured to expose a photosensitive member
with the light-emitting member, wherein the light-emitting member
comprises a member obtained by placing a plurality of the organic
light-emitting devices according to claim 1 along a predetermined
linear direction so that the devices form a line.
Description
TECHNICAL FIELD
[0001] The present invention relates to an organic compound and an
organic light-emitting device using the compound.
BACKGROUND ART
[0002] An organic light-emitting device is an electronic device
including a pair of electrodes and an organic compound layer placed
between the electrodes. An electron and a hole are injected from
the pair of electrodes, the electron and the hole recombine in the
organic compound layer to produce an exciton of a luminous organic
compound, and the organic light-emitting device emits light when
the exciton returns to its ground state.
[0003] Multiple elements for an improvement in emission efficiency
of the organic light-emitting device exist, and one of the elements
is to improve charge (hole and electron) injection/transport
properties. In addition, the research and development of a material
and device construction intended for the improvement of the charge
injection/transport properties have heretofore been performed.
[0004] Patent Literature 1 proposes that an improvement in hole
transport property be achieved by forming a hole transport layer
from a mixture of different hole transportable materials. In
addition, Patent Literature 2 discloses an organic light-emitting
device including a layer obtained by doping a tertiary amine
compound with rubrene or an anthracene compound. Further, Patent
Literature 3 and Patent Literature 4 propose compounds shown
below.
##STR00001##
CITATION LIST
Patent Literature
[0005] PTL 1: Japanese Patent Application Laid-Open No. 2000-68064
[0006] PTL 2: Japanese Patent Application Laid-Open No. 2003-77676
[0007] PTL 3: Japanese Patent Application Laid-Open No. 2007-314510
[0008] PTL 4: Japanese Patent Application Laid-Open No.
2007-314506
SUMMARY OF INVENTION
Technical Problem
[0009] The present invention has been made to solve the problems
and an object of the present invention is to provide an organic
light-emitting device capable of outputting light with high
efficiency and high luminance.
Solution to Problem
[0010] An organic light-emitting device according to one embodiment
of the present invention includes: an anode; a cathode; an emission
layer placed between the anode and the cathode; and an organic
compound layer placed between the anode and the emission layer,
wherein the organic compound layer contains the following compound
A and compound B:
[0011] [Compound A] an organic compound free of a nitrogen atom and
a metal atom, the compound having SP.sup.2 carbon atoms and
SP.sup.3 carbon atoms, and having a ratio of the number of the
SP.sup.3 carbon atoms to the number of the SP.sup.2 carbon atoms of
40% or more; and
[0012] [Compound B] a compound having a tertiary amine
structure.
Advantageous Effects of Invention
[0013] According to one embodiment of the present invention, it is
possible to provide the organic light-emitting device that outputs
light with high efficiency and high luminance. It should be noted
that the organic compound of the present invention does not cause
association between its molecules and has a wide band gap in a
film.
[0014] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a schematic sectional view of a display apparatus
including an organic light-emitting device and a switching device
connected to the organic light-emitting device.
DESCRIPTION OF EMBODIMENTS
[0016] Hereinafter, the present invention is described in
detail.
(1) Organic Light-Emitting Device
[0017] First, an organic light-emitting device of the present
invention is described. The organic light-emitting device of the
present invention includes: an anode; a cathode; an emission layer
placed between the anode and the cathode; and an organic compound
layer placed between the anode and the emission layer.
[0018] In the present invention, the organic compound layer
contains the following compound A and compound B:
[Compound A] an aromatic hydrocarbon compound having SP.sup.2
carbon atoms and SP.sup.3 carbon atoms, and having a ratio of the
number of the SP.sup.3 carbon atoms to the number of the SP.sup.2
carbon atoms of 40% or more; and [Compound B] a compound having a
tertiary amine structure.
[0019] In the present invention, specific constructions of the
organic light-emitting device include at least the following
constructions (A) to (C).
(A) (Substrate/) anode/hole transport layer/emission layer/electron
transport layer/cathode (B) (Substrate/) anode/hole injection
layer/hole transport layer/emission layer/electron transport
layer/cathode (C) (Substrate/) anode/hole transport layer/emission
layer/hole.cndot. exciton-blocking layer/electron transport
layer/cathode
[0020] It should be noted that the present invention is not limited
to the aspects (A) to (C). In particular, for example, the
following aspects (D) and (E) can also be included in the specific
constructions of the organic light-emitting device depending on the
compound A in the organic compound layer.
(D) (Substrate/) anode/emission layer/cathode (E) (Substrate/)
anode/hole transport layer/electron transport layer/cathode.
[0021] It should be noted that specific examples of the compound A
capable of adopting not only the aspects (A) to (C) but also the
aspects (D) and (E) are described later. In addition, in the case
of the construction (E), an interface between the hole transport
layer and the electron transport layer emits light.
[0022] In the present invention, the following may be adopted: the
cathode constituting the organic light-emitting device is formed on
the substrate as an electrode close to the substrate before the
respective layers are formed.
[0023] In the present invention, the organic compound layer
incorporated into the organic light-emitting device as a layer
different from the emission layer is a layer formed between the
anode and the emission layer as described above. At this time, the
layer construction of the organic compound layer is not limited to
a single layer and may be a laminate formed of multiple layers. In
the present invention, the organic compound layer in the organic
light-emitting device is preferably a layer having a function of
transporting a hole, and is specifically a hole injection layer, a
hole transport layer, or a laminate obtained by laminating a hole
injection layer and a hole transport layer.
[0024] Here, the SP.sup.2 carbon atoms in the compound A are carbon
atoms for forming an unsaturated carbon-carbon bond (C.dbd.C) and
are carbon atoms constituting mainly the main skeleton of the
aromatic hydrocarbon compound. In addition, the SP.sup.3 carbon
atoms in the compound A are carbon atoms for forming a saturated
carbon-carbon bond (C--C) and are carbon atoms constituting mainly
an alkyl group bonded to the main skeleton of the aromatic
hydrocarbon compound.
[0025] In the present invention, the compound A is preferably a
compound represented by the following general formula [1] or
[2].
Z.sub.1 Ar.sub.1).sub.n [1]
Ar.sub.2--Ar.sub.3 [2]
[0026] In the general formula [1], Z.sub.1 represents an aryl group
(aromatic hydrocarbon group), an aliphatic condensed polycyclic
group, a carbon atom, or an oxygen atom.
[0027] Examples of the aryl group represented by Z.sub.1 include: a
monovalent aryl group such as a phenyl group, a naphthyl group, a
pentalenyl group, an indenyl group, an azulenyl group, an anthryl
group, a pyrenyl group, an indacenyl group, an acenaphthenyl group,
a phenanthryl group, a phenalenyl group, a fluoranthenyl group, an
acephenanthryl group, an aceanthryl group, a triphenylenyl group, a
chrysenyl group, a naphthacenyl group, a perylenyl group, a
pentacenyl group, a biphenyl group, a terphenyl group, or a
fluorenyl group; and a 2- to 6-valent aryl group derived from the
monovalent aryl group (that is, a 2- to 6-valent aryl group
obtained by removing 1 to 5 hydrogen atoms from the monovalent aryl
group).
[0028] Examples of the aliphatic condensed polycyclic group
represented by Z.sub.1 include ring structures listed below.
##STR00002##
[0029] It should be noted that the substituent (aryl group,
aliphatic condensed polycyclic group, carbon atom, or oxygen atom)
represented by Z.sub.1 may further have: an alkyl group such as a
methyl group, an ethyl group, an n-propyl group, an isopropyl
group, an n-butyl group, a tert-butyl group, a sec-butyl group, an
octyl group, a 1-adamantyl group, a 2-adamantyl group, a cyclohexyl
group, a cyclopentyl group, or a cyclohexylmethyl group; an alkoxy
group such as a methoxy group, an ethoxy group, an isopropoxy
group, an n-propoxy group, a sec-butoxy group, a tert-butoxy group,
or an octoxy group; an aryl group such as a phenyl group or a
phenyl group having an alkyl group; or a halogen atom such as
chlorine, bromine, or fluorine. Here, when the aryl group further
has an alkyl group, the alkyl group is preferably an alkyl group
having 10 or less carbon atoms such as an isopropyl group, an
n-propyl group, an n-butyl group, a sec-butyl group, a tert-butyl
group, an isoamyl group, an adamantyl group, a cyclohexyl group, a
cyclopentyl group, or a cyclohexylmethyl group. Any such
substituent promotes the lengthening of the lifetime of the organic
light-emitting device because the substituent has good heat
stability, plays a considerable role in preventing molecular
association in a film, and suppresses the crystallization of the
film. Of those, a branched alkyl group such as an isopropyl group,
a tert-butyl group, an isoamyl group, an adamantyl group, a
cyclohexyl group, a cyclopentyl group, or a cyclohexylmethyl group
is more preferred. The presence of any such substituent improves
the heat stability of the compound itself. Here, when the aryl
group further has an alkoxy group, the aryl group is preferably
substituted with an alkoxy group having 10 or less carbon atoms
such as an isopropoxy group, an n-propoxy group, a sec-butoxy
group, or a tert-butoxy group as the alkoxy group, and an alkoxy
group having a branched alkyl group such as an isopropoxy group, a
sec-butoxy group, or a tert-butoxy group is more preferred. In
addition, when the aryl group further has a halogen atom, the
halogen atom is preferably fluorine.
[0030] In the general formula [1], Ar.sub.1 represents an aryl
group, an aliphatic condensed polycyclic group, a carbon atom, or
an oxygen atom. Specific examples of the aryl group and aliphatic
condensed polycyclic group each represented by Ar.sub.1 are the
same as the specific examples of the aryl group and aliphatic
condensed polycyclic group each represented by Z.sub.1. In
addition, when Ar.sub.1 represents an aryl group, the aryl group
may further have a substituent and specific examples of the
substituent are the same as the specific examples of the
substituent which the aryl group represented by Z.sub.1 may further
have. In the general formula [1], Ar.sub.1 preferably represents a
phenyl group having an alkyl group, a fluorenyl group having an
alkyl group, a biphenyl group having an alkyl group, or a naphthyl
group having an alkyl group.
[0031] In the general formula [1], n represents an integer of 1 to
6, provided that when Z.sub.1 represents a carbon atom, n
represents an integer of 1 to 4, and when Z.sub.1 represents an
oxygen atom, n represents 1 or 2. When n represents 2 or more,
structures Ar.sub.1's in parentheses may be identical to or
different from each other.
[0032] In the general formula [2], Ar.sub.2 and Ar.sub.3 each
represent an aryl group or an aliphatic condensed polycyclic group.
Specific examples of the aryl group and aliphatic condensed
polycyclic group represented by Ar.sub.2 and Ar.sub.3 are the same
as the specific examples of the aryl group and aliphatic condensed
polycyclic group each represented by Z.sub.1 in the formula [1]. In
addition, when any one of Ar.sub.2 and Ar.sub.3 represents an aryl
group, the aryl group may further have a substituent and specific
examples of the substituent are the same as the specific examples
of the substituent which the aryl group represented by Z.sub.1 in
the formula [1] may further have. The substituent represented by
Ar.sub.2 or Ar.sub.3 in the general formula [2] is preferably a
phenyl group having an alkyl group, a fluorenyl group having an
alkyl group, a biphenyl group having an alkyl group, or a naphthyl
group having an alkyl group.
[0033] Next, the compound B is described. The tertiary amine
structure of the compound B refers to a structure formed of a
nitrogen atom and three kinds of substituents except hydrogen
bonded to the nitrogen atom. The compound B is a compound
containing one or more tertiary amine structures of this type. In
addition, the compound may be a low-molecular weight compound or
may be a high-molecular weight compound.
[0034] When the compound having a tertiary amine structure serving
as the compound B is, for example, a low-molecular weight compound,
the compound is any one of the compounds listed in the following
general formulae [11] to [17].
##STR00003##
[0035] In the general formulae [11] to [17], Ar.sub.21 to
Ar.sub.27, Ar.sub.30 to Ar.sub.35, Ar.sub.38 to Ar.sub.42,
Ar.sub.46 to Ar.sub.51, Ar.sub.55 to Ar.sub.60, and Ar.sub.61 to
Ar.sub.64 each represent a substituted or unsubstituted, monovalent
aryl group, a substituted or unsubstituted, monovalent heterocyclic
group, or a substituted or unsubstituted, monovalent alkyl group.
In the general formula [17], m represents an integer of 1 to 5.
[0036] In addition, when the compound B is a high-molecular weight
compound, the compound is, for example, a polymer compound having
any one of the general formulae [11] to [17] as a repeating
unit.
[0037] Examples of the monovalent aryl group include monovalent
substituents such as a phenyl group, a naphthyl group, a pentalenyl
group, an indenyl group, an azulenyl group, an anthryl group, a
pyrenyl group, an indacenyl group, an acenaphthenyl group, a
phenanthryl group, a phenalenyl group, a fluoranthenyl group, an
acephenanthryl group, an aceanthryl group, a triphenylenyl group, a
chrysenyl group, a naphthacenyl group, a perylenyl group, a
pantacenyl group, a biphenyl group, a terphenyl group, and a
fluorenyl group.
[0038] Examples of the monovalent heterocyclic group include
monovalent substituents such as a thienyl group, a pyrrolyl group,
a pyridyl group, an oxazolyl group, an oxadiazolyl group, a
thiazolyl group, a thiadiazolyl group, a terthienyl group, a
dibenzothiophenyl group, a dibenzofuryl group, and a phenanthryl
group.
[0039] Examples of the monovalent alkyl group include monovalent
alkyl groups such as a methyl group, an ethyl group, an n-propyl
group, an isopropyl group, an n-butyl group, a tert-butyl group, a
sec-butyl group, an octyl group, a 1-adamantyl group, and a
2-adamantyl group. Of those, an alkyl group having 4 or less carbon
atoms such as a methyl group, an ethyl group, an n-propyl group, an
isopropyl group, an n-butyl group, a tert-butyl group, or a
sec-butyl group is preferred.
[0040] As a substituent that the monovalent aryl group, the
monovalent heterocyclic group, or the monovalent alkyl group may
have, there are given, for example: an alkyl group such as a methyl
group, an ethyl group, an n-propyl group, an isopropyl group, an
n-butyl group, a tert-butyl group, a sec-butyl group, an octyl
group, a 1-adamantyl group, or a 2-adamantyl group; an aryl group
such as a phenyl group, a naphthyl group, a pentalenyl group, an
indenyl group, an azulenyl group, an anthryl group, a pyrenyl
group, an indacenyl group, an acenaphthenyl group, a phenanthryl
group, a phenalenyl group, a fluoranthenyl group, an acephenanthryl
group, an aceanthryl group, a triphenylenyl group, a chrysenyl
group, a naphthacenyl group, a perylenyl group, a pentacenyl group,
a biphenyl group, a terphenyl group, or a fluorenyl group; a
heterocyclic group such as a thienyl group, a pyrrolyl group, a
pyridyl group, an oxazolyl group, an oxadiazolyl group, an
thiazolyl group, a thiadiazolyl group, a terthienyl group, a
dibenzothiophenyl group, a dibenzofuryl group, or a phenanthryl
group; a substituted amino group such as a dimethylamino group, a
diethylamino group, a dibenzylamino group, a diphenylamino group, a
ditolylamino group, or a dianisoylamino group; an alkoxy group such
as a methoxy group, an ethoxy group, or a propoxy group (preferably
an alkoxy group having 4 or less carbon atoms, e.g., a methoxy
group, an ethoxy group, a propoxy group, or an n-butoxy group); an
aryloxy group such as a phenoxy group; a halogen atom such as
fluorine, chlorine, bromine, or iodine (preferably a fluorine
atom); and a cyano group.
[0041] In the general formulae [11] to [17], Ar.sub.28, Ar.sub.29,
Ar.sub.36, Ar.sub.37, Ar.sub.43 to Ar.sub.45, Ar.sub.52 to
Ar.sub.54, and Ar.sub.65 to Ar.sub.68 each represent a substituted
or unsubstituted, divalent aryl group, a substituted or
unsubstituted, divalent heterocyclic group, or a substituted or
unsubstituted, divalent alkyl group.
[0042] Examples of the divalent aryl group include divalent
substituents derived from a phenyl group, a naphthyl group, a
pentalenyl group, an indenyl group, an azulenyl group, an anthryl
group, a pyrenyl group, an indacenyl group, an acenaphthenyl group,
a phenanthryl group, a phenalenyl group, a fluoranthenyl group, an
acephenanthryl group, an aceanthryl group, a triphenylenyl group, a
chrysenyl group, a naphthacenyl group, a perylenyl group, a
pantacenyl group, a biphenyl group, a terphenyl group, and a
fluorenyl group.
[0043] Examples of the divalent heterocyclic group include divalent
substituents derived from a thienyl group, a pyrrolyl group, a
pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl
group, a thiadiazolyl group, a terthienyl group, a
dibenzothiophenyl group, a dibenzofuryl group, and a phenanthryl
group.
[0044] Examples of the divalent alkyl group include divalent alkyl
groups derived from a methyl group, an ethyl group, an n-propyl
group, an isopropyl group, an n-butyl group, a tert-butyl group, a
sec-butyl group, an octyl group, a 1-adamantyl group, and a
2-adamantyl group. Of those, a divalent substituent derived from an
alkyl group having 4 or less carbon atoms such as a methyl group,
an ethyl group, an n-propyl group, an isopropyl group, an n-butyl
group, a tert-butyl group, or a sec-butyl group is preferred.
[0045] As a substituent that the aryl group, the heterocyclic
group, or the alkyl group may have, there are given, for example:
an alkyl group such as a methyl group, an ethyl group, an n-propyl
group, an isopropyl group, an n-butyl group, a tert-butyl group, a
sec-butyl group, an octyl group, a 1-adamantyl group, or a
2-adamantyl group; an aryl group such as a phenyl group, a naphthyl
group, a pentalenyl group, an indenyl group, an azulenyl group, an
anthryl group, a pyrenyl group, an indacenyl group, an
acenaphthenyl group, a phenanthryl group, a phenalenyl group, a
fluoranthenyl group, an acephenanthryl group, an aceanthryl group,
a triphenylenyl group, a chrysenyl group, a naphthacenyl group, a
perylenyl group, a pentacenyl group, a biphenyl group, a terphenyl
group, or a fluorenyl group; a heterocyclic group such as a thienyl
group, a pyrrolyl group, a pyridyl group, an oxazolyl group, an
oxadiazolyl group, an thiazolyl group, a thiadiazolyl group, a
terthienyl group, a dibenzothiophenyl group, a dibenzofuryl group,
or a phenanthryl group; a substituted amino group such as a
dimethylamino group, a diethylamino group, a dibenzylamino group, a
diphenylamino group, a ditolylamino group, or a dianisoylamino
group; an alkoxy group such as a methoxy group, an ethoxy group, or
a propoxy group (preferably an alkoxy group having 4 or less carbon
atoms, e.g., a methoxy group, an ethoxy group, a propoxy group, or
an n-butoxy group); an aryloxy group such as a phenoxy group; a
halogen atom such as fluorine, chlorine, bromine, or iodine
(preferably a fluorine atom); and a cyano group.
[0046] In the general formula [11], Ar.sub.21 to Ar.sub.23 may be
identical to or different from one another. In addition, any one of
the combinations of Ar.sub.21 and Ar.sub.22, Ar.sub.21 and
Ar.sub.23, and Ar.sub.22 and Ar.sub.23 may wind in a ring (that is,
for example, Ar.sub.21 and Ar.sub.22 may be bonded to turn into
--Ar.sub.21--Ar.sub.22--, thereby forming a ring with N) to form a
nitrogen-containing heterocyclic skeleton such as a carbazole
skeleton.
[0047] In the general formula [12], Ar.sub.24 to Ar.sub.27 may be
identical to or different from one another. In addition, any one of
the combinations of Ar.sub.24 and Ar.sub.25, and Ar.sub.26 and
Ar.sub.27 may wind in a ring to form a nitrogen-containing
heterocyclic skeleton such as a carbazole skeleton.
[0048] In the general formula [13], Ar.sub.30 to Ar.sub.35 may be
identical to or different from one another. In addition, any one of
the combinations of Ar.sub.30 and Ar.sub.31, Ar.sub.32 and
Ar.sub.33, and Ar.sub.34 and Ar.sub.35 may wind in a ring to form a
nitrogen-containing heterocyclic skeleton such as a carbazole
skeleton.
[0049] In the general formula [14], Ar.sub.36 and Ar.sub.37 may be
identical to or different from each other. In addition, in the
general formula [14], Ar.sub.38 to Ar.sub.42 may be identical to or
different from one another. In addition, any one of the
combinations of Ar.sub.38 and Ar.sub.39, and Ar.sub.40 and
Ar.sub.41 may wind in a ring to form a nitrogen-containing
heterocyclic skeleton such as a carbazole skeleton.
[0050] In the general formula [15], Ar.sub.43 to Ar.sub.45 may be
identical to or different from one another. In addition, in the
general formula [15], Ar.sub.46 to Ar.sub.51 may be identical to or
different from one another. In addition, any one of the
combinations of Ar.sub.46 and Ar.sub.47, and Ar.sub.49 and
Ar.sub.50 may wind in a ring to form a nitrogen-containing
heterocyclic skeleton such as a carbazole skeleton.
[0051] In the general formula [16], Ar.sub.52 to Ar.sub.54 may be
identical to or different from one another. In addition, in the
general formula [16], Ar.sub.55 to Ar.sub.60 may be identical to or
different from one another. In addition, any one of the
combinations of Ar.sub.55 and Ar.sub.56, Ar.sub.57 and Ar.sub.58,
and Ar.sub.59 and Ar.sub.60 may wind in a ring to form a
nitrogen-containing heterocyclic skeleton such as a carbazole
skeleton.
[0052] In the general formula [17], Ar.sub.61 to Ar.sub.63 may be
identical to or different from one another. In addition, in the
general formula [17], Ar.sub.65 to Ar.sub.68 may be identical to or
different from one another. In addition, a compound according to
the general formula [17] comprehends a polymer compound having a
large number (m value) of repeating units.
[0053] The organic light-emitting device of the present invention
includes at least one organic compound layer (such as a hole
transport layer or an electron-blocking layer) between the anode
and the emission layer. In addition, the organic compound layer
contains the compound A and the compound B. Thus, the organic
light-emitting device of the present invention has good emission
efficiency.
[0054] The inventors of the present invention have produced an
organic light-emitting device having a device construction shown in
Table 1 below by using compounds shown below with a view to
investigating the operation and effect of the incorporation of the
compound A and the compound B into the organic compound layer
formed between the anode and the emission layer. It should be noted
that multiple compounds different from each other in SP.sup.3
carbon atom content were prepared as compounds each serving as the
compound A. Details about the foregoing are described below.
<Compound Used as Compound A>
##STR00004## ##STR00005## ##STR00006##
[0055]<Compound Used as Compound B>
##STR00007##
[0056]<Others>
##STR00008##
TABLE-US-00001 [0057] TABLE 1 Constituent material Thickness [nm]
Anode ITO -- Organic compound layer Compound A 30 Compound B (BC-4)
(compound A:compound B = 2:1 (weight ratio)) Emission layer c-2
(host) 20 c-1 (guest) (host:guest = 95:5 (weight ratio))
Hole-blocking layer c-3 40 Electron transport layer c-4 20 First
electrode layer LiF 0.5 (cathode) Second electrode layer Al 1,500
(cathode)
[0058] The produced organic light-emitting device was evaluated for
its emission efficiency, external quantum yield, and chromaticity
coordinates when caused to emit light under the condition of 2,000
cd/m.sup.2.
[0059] By the way, the relative ratio (%) of the SP.sup.3 carbon
atoms in the compound A can be determined from the following
equation. It should be noted that the resultant value is rounded
off to the nearest integer. [Number of SP.sup.3 carbon atoms in
compound A]/[number of SP.sup.2 carbon atoms in compound
A].times.100
[0060] Table 2 below shows the results of the evaluations of the
emission efficiency, the external quantum yield, and the
chromaticity coordinates.
TABLE-US-00002 TABLE 2 SP.sup.3 Compound carbon atom Emission
External Chromaticity used as [relative efficiency quantum yield
coordinates compound A ratio, %] [cd/A] [%] [x, y] AC-6 109 13.0
7.0 (0.15, 0.26) AA-1 92 11.7 6.5 (0.16, 0.26) AA-7 87 11.3 6.3
(0.16, 0.26) AA-9 65 11.1 6.2 (0.16, 0.26) AB-3 53 12.3 6.9 (0.16,
0.25) AB-7 44 11.5 6.6 (0.15, 0.25) AB-6 42 12.1 6.8 (0.15, 0.25)
AZ-1 25 8.8 4.9 (0.16, 0.24) AZ-2 0 --.sup.[Note 1] AZ-3 0 7.8 4.3
(0.15, 0.25) (None) -- 8.3 4.7 (0.15, 0.25) .sup.[Note 1]AZ-2 emits
light.
[0061] It is understood from Table 2 that the emission efficiency
is improved by incorporating, into the organic compound layer
formed between the anode and the emission layer, a compound having
a relative ratio (%) of the SP.sup.3 carbon atoms of 40% or more
out of the organic compounds each used as the compound A together
with the compound B as a hole transportable compound.
[0062] The result probably originates from the fact that an
operation and effect described below are exhibited.
[0063] SP.sup.3 carbon atoms generally have the following features
(1a-1) and (1a-2):
(1a-1) a feature that an SP.sup.3 carbon atom suppresses
intermolecular stacking in a film to suppress the contraction of a
band gap; and (1a-2) a feature that there is no absorption (derived
from a substituent (such as an alkyl group or an aliphatic
condensed polycyclic group) constituted of an SP.sup.3 carbon
atom)) in a visible region.
[0064] Meanwhile, SP.sup.2 carbon atoms generally have the
following features (1b-1) and (1b-2):
(1b-1) a feature that the SP.sup.2 carbon atoms each generally have
absorption in the visible region (an absorption region shifts to
longer wavelengths as the linking number of their aromatic rings
increases or the number of their condensed rings increases); and
(1b-2) a feature that a band gap contraction effect in which a band
gap in a thin-film state narrows as compared with that in a dilute
solution state occurs.
[0065] It should be noted that the feature (1b-2) is a feature
caused by the fact that a stacking interaction is strengthened by
the presence of a large amount of electrons delocalized by
n-electron systems on a rigid planar structure and SP.sup.2 hybrid
orbital. In addition, the feature (1b-2) becomes more significant
as the number of .pi.-electrons increases.
[0066] In view of the foregoing, increasing the relative ratio (%)
of (the number of) the SP.sup.3 carbon atoms in the compound A to
the number of the SP.sup.2 carbon atoms in the compound A leads to
a preventing effect on the contraction of the band gap of the
compound B as a compound containing a tertiary amine structure.
Thus, the diffusion and injection of an exciton and electron from
the emission layer can be suppressed. As a result, the emission
efficiency improves.
[0067] In contrast, when a compound having a low (less than 40%)
relative ratio of (the number of) SP.sup.3 carbon atoms or a
relative ratio of zero, e.g., Compound AZ-2 is used as the compound
A, the band gap additionally narrows and hence light emission from
AZ-2 is observed. Accordingly, an emission spectrum derived from
Compound c-1 incorporated into the emission layer as a dopant is
not obtained. In addition, when any one of Compounds AZ-1 and AZ-3
is used, the resultant efficiency is substantially the same as that
of an organic light-emitting device that does not contain a
compound serving as the compound A and hence no improvement is
observed.
[0068] The matters described above are summarized as follows:
[0069] the emission efficiency improves as an SP.sup.3 carbon atom
in an alkyl group or the like of an organic compound corresponding
to the compound A is incorporated in a certain amount or more, in
other words, the ratio of a substituent (such as an alkyl group)
formed of an SP.sup.3 carbon atom in a molecule increases. In
addition, as shown in Table 2, the improving effect on the emission
efficiency appears when the relative ratio (%) of the SP.sup.3
carbon atoms is 40% or more. In the present invention, the relative
ratio (%) of the number of the SP.sup.3 carbon atoms in the
compound A to the number of the SP.sup.2 carbon atoms in the
compound A is preferably 80% or more.
[0070] However, it is not preferred to use a compound formed only
of an SP.sup.3 carbon atom as the compound A because the compound
inhibits carrier transport. Accordingly, a carrier-transporting
function needs to be secured by incorporating a certain amount of
an SP.sup.2 carbon atom into the compound.
[0071] The structure and substituent of the compound A are not
particularly limited as long as the compound has a relative ratio
(%) of the SP.sup.3 carbon atoms of 40% or more. However, the
compound is preferably of a structure free of a nitrogen atom and a
metal atom because the difficulty with which the compound interacts
with the compound B is preferably high.
[0072] In addition, Ar.sub.2 and Z.sub.1 in the general formula
[1], and Ar.sub.2 and Ar.sub.3 in the general formula [2] are each
more preferably of a structure having a wide band gap.
Specifically, the structure contains an aryl group such as a phenyl
group, a fluorenyl group, a biphenyl group, or a naphthyl group.
This is because the structure has suppressing effects on the
movement of an exciton and the injection of an electron.
[0073] In addition, a mixing ratio between the compound A and
compound B in the organic compound layer is not particularly
limited. However, a higher ratio of the compound A may improve the
emission efficiency and a higher ratio of the compound B may reduce
the driving voltage of the device. Accordingly, when compatibility
between high efficiency and low-voltage driving is to be achieved,
the ratio (mixing ratio, weight base) of the compound B in the
organic compound layer is preferably 10 wt % to 90 wt %, more
preferably 20 wt % to 70 wt % with reference to the total of the
compound A and the compound B.
[0074] It should be noted that in the present invention, an assist
material that may promote carrier injection may be incorporated
into the organic compound layer in addition to the compound A and
the compound B.
[0075] Specific examples of the compound A are shown below.
##STR00009## ##STR00010## ##STR00011## ##STR00012## ##STR00013##
##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018##
##STR00019## ##STR00020##
[0076] Of the listed compounds, Exemplified Compounds AA-1 to AA-35
are each a compound having the following feature: the compound has
a wide band gap and a high glass transition temperature.
[0077] Of the listed compounds, Exemplified Compounds AB-1 to AB-11
are a group of compounds in each of which Ar.sub.1 represents, or
Ar.sub.2 and Ar.sub.3 each represent, a biphenyl group. Each
compound belonging to the compound group has a wide band gap and a
low sublimation temperature because the compound has a rotation
axis in a biphenyl skeleton.
[0078] Of the listed compounds, Exemplified Compounds AC-1 to AC-17
are a group of compounds in each of which Ar.sub.1 represents, or
Ar.sub.2 and Ar.sub.3 each represent, a phenyl group. Here, in the
compound group, a compound having a wide band gap is easily
designed because the band gap of a phenyl group is wide. In
addition, the sublimation temperature of the compound can be
reduced because its molecular weight can be reduced.
[0079] Of the listed compounds, Exemplified Compounds AD-1 to AD-5
are a group of compounds in each of which Ar.sub.1 represents, or
Ar.sub.2 and Ar.sub.3 each represent, a naphthyl group. Each
compound belonging to the compound group has the following feature:
the compound has a wide band gap and a high glass transition
temperature.
[0080] Of the listed compounds, Exemplified Compounds AE-1 to AE-3
are a group of compounds in each of which Ar.sub.1 represents, or
Ar.sub.2 and Ar.sub.3 each represent, a phenanthryl group. Each
compound belonging to the compound group has the following feature:
the compound has a wide band gap and a high glass transition
temperature, though having a large molecular weight.
[0081] Next, specific examples of the compound B are shown.
##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##
##STR00026## ##STR00027## ##STR00028##
[0082] The organic light-emitting device of the present invention,
in particular, the compound A (organic compound free of a nitrogen
atom and a metal atom) and the compound B (compound having a
tertiary amine structure) as main constituent materials have been
described above. However, the constituent materials for the organic
light-emitting device of the present invention are not limited to
the compound A and the compound B. It should be noted that any
other constituent material to be incorporated into the organic
light-emitting device of the present invention is separately
described.
(2) Organic Compound
[0083] Next, an organic compound of the present invention is
described. The organic compound of the present invention is a
compound represented by the following general formula [3] or
[4].
##STR00029##
[0084] In the general formula [3], Z.sub.2 represents a naphthyl
group, a fluorenyl group, a phenanthryl group, a triphenylenyl
group, an aliphatic condensed polycyclic group, a carbon atom, or
an oxygen atom. That is, Z.sub.2 represents a monovalent group,
i.e., a naphthyl group, a fluorenyl group, a phenanthryl group, or
a triphenylenyl group, a 2- to 6-valent group derived from the
monovalent group, an aliphatic condensed polycyclic group, a carbon
atom, or an oxygen atom. It should be noted that the substituent
represented by Z.sub.2 may further have an alkyl group, an alkoxy
group, an aryl group, or a halogen atom. It is preferred that
Z.sub.2 represent an aliphatic condensed polycyclic group, carbon
atom, or oxygen atom that may further have an alkyl group, an
alkoxy group, an aryl group, or a halogen atom.
[0085] Examples of the aliphatic condensed polycyclic group
represented by Z.sub.2 include substituents derived from aliphatic
condensed polycyclic compounds shown below.
##STR00030##
[0086] It should be noted that the substituent represented by
Z.sub.2 may further have: an alkyl group such as a methyl group, an
ethyl group, an n-propyl group, an isopropyl group, an n-butyl
group, a tert-butyl group, a sec-butyl group, an octyl group, a
1-adamantyl group, a 2-adamantyl group, a cyclohexyl group, a
cyclopentyl group, or a cyclohexylmethyl group; an alkoxy group
such as a methoxy group, an ethoxy group, an isopropoxy group, an
n-propoxy group, a sec-butoxy group, a tert-butoxy group, or an
octoxy group; an aryl group such as a phenyl group or a phenyl
group having an alkyl group; or a halogen atom such as chlorine,
bromine, or fluorine.
[0087] In the general formula [3], R.sub.1 to R.sub.9 each
represent a hydrogen atom, an alkyl group, an alkoxy group, or a
halogen atom, provided that at least two of the substituents
represented by R.sub.1 to R.sub.9 are alkyl groups.
[0088] In the general formula [3], m represents an integer of 1 to
6, provided that when Z.sub.2 represents a carbon atom, m
represents 1 to 4, and when Z.sub.2 represents an oxygen atom, m
represents 1 or 2. When m represents 2 or more, structures in
parentheses may be identical to or different from each other.
[0089] m preferably represents 2 or more because crystallinity is
reduced and film property is improved.
[0090] In the general formula [4], R.sub.11 to R.sub.28 each
represent a hydrogen atom, an alkyl group, an alkoxy group, or a
halogen atom, provided that at least two of the substituents
represented by R.sub.11 to R.sub.28 are alkyl groups.
[0091] The alkyl group represented by any one of R.sub.1 to R.sub.9
and R.sub.11 to R.sub.28 is preferably an alkyl group having 10 or
less carbon atoms. Examples thereof include a methyl group, an
ethyl group, an n-propyl group, an isopropyl group, an n-butyl
group, a tert-butyl group, a sec-butyl group, an octyl group, an
isoamyl group, a 1-adamantyl group, a 2-adamantyl group, a
cyclohexyl group, a cyclopentyl group, and a cyclohexylmethyl
group. The introduction of any such substituent improves the heat
stability of the compound itself. In addition, the introduction of
any such substituent can prevent intermolecular association when
the compound is formed into a film, and hence can suppress the
crystallization of the film and provide a long-lifetime organic
light-emitting device. Of those, a branched alkyl group such as an
isopropyl group, a tert-butyl group, an isoamyl group, an adamantyl
group, a cyclohexyl group, a cyclopentyl group, or a
cyclohexylmethyl group is more preferred. This is because the
introduction of any one of those substituents additionally improves
the heat stability of the compound itself.
[0092] The alkoxy group represented by any one of R.sub.1 to
R.sub.9 and R.sub.11 to R.sub.28 is preferably an alkoxy group
having 10 or less carbon atoms. Examples thereof include a methoxy
group, an ethoxy group, an isopropoxy group, an n-propoxy group, a
sec-butoxy group, a tert-butoxy group, and an octoxy group. Of
those, an alkoxy group in which a branched alkyl is introduced such
as an isopropoxy group, a sec-butoxy group, or a tert-butoxy group
is more preferred.
[0093] Examples of the halogen atom represented by any one of
R.sub.1 to R.sub.9 and R.sub.11 to R.sub.28 include chlorine,
bromine, and fluorine. Of those, fluorine is preferred because it
has a large preventing effect on the association of fluorene
skeletons in the molecules.
[0094] In the present invention, the organic compound represented
by the general formula [3] is preferably an organic compound
represented by the following general formula [5]. In addition, the
organic compound represented by the general formula [4] is
preferably an organic compound represented by the following general
formula [6].
##STR00031##
[0095] In the general formula [5], Z.sub.11 represents a naphthyl
group, a fluorenyl group, a phenanthryl group, a triphenylenyl
group, an aliphatic condensed polycyclic group, a carbon atom, or
an oxygen atom. It should be noted that the substituent represented
by Z.sub.11 may further have an alkyl group, an alkoxy group, an
aryl group, or a halogen atom. It is preferred that Z.sub.11
represent an aliphatic condensed polycyclic group, carbon atom, or
oxygen atom that may further have an alkyl group, an alkoxy group,
an aryl group, or a halogen atom.
[0096] Specific examples of the aliphatic condensed polycyclic
group represented by Z.sub.11 are the same as the specific examples
of the aliphatic condensed polycyclic group represented by Z.sub.2
in the general formula [3]. In addition, specific examples of the
alkyl group, alkoxy group, aryl group, or halogen atom which the
substituent represented by Z.sub.11 may further have are the same
as the specific examples of the alkyl group, alkoxy group, aryl
group, or halogen atom which the substituent represented by Z.sub.2
in the general formula [3] may further have.
[0097] In the general formula [5], m represents an integer of 1 to
6, provided that when Z.sub.11 represents a carbon atom, m
represents 1 to 4, and when Z.sub.11 represents an oxygen atom, m
represents 1 or 2. When m represents 2 or more, structures in
parentheses may be identical to or different from each other.
[0098] R.sub.2, R.sub.6, R.sub.8, R.sub.9, R.sub.12, R.sub.16,
R.sub.18, R.sub.19, R.sub.21, R.sub.24, R.sub.27, and R.sub.28 each
represent an alkyl group or an alkoxy group, and may be identical
to or different from one another. In the present invention,
R.sub.2, R.sub.6, R.sub.8, and R.sub.9 in the general formula [5],
and R.sub.12, R.sub.16, R.sub.18, R.sub.19, R.sub.21, R.sub.24,
R.sub.27, and R.sub.28 in the general formula [6] each preferably
represent an alkyl group or an alkoxy group. The reason for the
foregoing is that the substitution of any one of the 2-, 7-, and
9-positions of a fluorene skeleton with an alkyl group or an alkoxy
group can surely prevent the association of fluorene skeletons
between molecules. In other words, when a compound is formed into a
film, the occurrence of intermolecular association lengthens the
wavelength of its band gap as compared with that in a dilute
solution state, but each of the organic compounds represented by
the general formulae [3] and [4] can prevent the lengthening of the
wavelength of its band gap because intermolecular association is
suppressed even when the compound is formed into a film.
[0099] Each of the organic compounds represented by the general
formulae [3] to [6] has such features as described below:
(i) the compound has a wide band gap and the first peak value (peak
value at the longest wavelength) of its absorption spectrum in a
dilute solution is less than 400 nm; and (ii) the compound has a
high lowest excited triplet state (T.sub.1) and the first peak
value (peak value at the shortest wavelength) of its
phosphorescence emission spectrum in a low-temperature dilute
solution is less than 520 nm.
[0100] As described later, the fluorene skeleton as a mother
skeleton in the organic compound of the present invention is a
skeleton having a first peak value of its absorption spectrum in a
dilute solution state of 303 nm and having a wide band gap. In
addition, the organic compound represented by the general formula
[3] is such a compound that a carbon atom at the 4-position of the
fluorene skeleton is substituted with the substituent Z.sub.2, but
the introduction of a substituent to the 4-position of the fluorene
skeleton enlarges steric hindrance. In that case, conjugation
between the substituent Z.sub.2 and the fluorene skeleton is
broken, and hence the band gap of the compound itself originates
from the structure of one having the narrower band gap out of
Z.sub.2 and the fluorene skeleton.
[0101] By the way, Z.sub.2 represents a divalent or more aromatic
hydrocarbon group, aliphatic condensed polycyclic group, carbon
atom, or oxygen atom that may have a substituent (an alkyl group,
an alkoxy group, an aryl group, or a halogen atom). In particular,
when Z.sub.2 represents an aromatic hydrocarbon group, the compound
is selected from aromatic hydrocarbon compounds each having a first
peak value of its absorption spectrum in a dilute solution in a
dilute solution state of less than 400 nm and each having a wide
band gap.
[0102] Here, as shown in Table 3 below, for example, the absorption
first peak wavelengths of triphenylene and phenanthrene are 336 nm
and 352 nm, respectively.
TABLE-US-00003 TABLE 3 Absorption first peak T.sub.1 Compound
wavelength [nm] [nm] c-11 (Triphenylene) 336 435 c-12
(Phenanthrene) 352 462 c-13 (Fluorene) 303 429 c-21 (Fluoranthene)
362 540 c-22 (Benzofluoranthene) 405 566
[0103] Thus, the organic compound of the present invention has a
wide band gap and the first peak value of its absorption spectrum
in a dilute solution is maintained at less than 400 nm. In
addition, the organic compound represented by the general formula
[3] is of a structure in which each of multiple fluorene skeletons
has a bonding hand with Z.sub.2 at its 4-position. Accordingly, the
first peak value of its absorption spectrum in a dilute solution is
maintained at less than 400 nm.
[0104] Here, the organic compound of the present invention, and
organic compounds (Compounds C-1 to C-3) according to Patent
Literatures 3 and 4 listed below are compared from the viewpoint of
the first peak value of an absorption spectrum in a dilute
solution.
##STR00032## ##STR00033##
[0105] Compounds C-1 to C-3 above each have a fluoranthene skeleton
or a benzofluoranthene skeleton in itself. However, fluoranthene
and benzofluoranthene have narrow band gaps, and hence the first
peak value of the absorption spectrum of each of the compounds in a
dilute solution is 400 nm or more. For example, the first peak
value of Compound C-1 is 405 nm.
[0106] The tendency concerning the band gap described above holds
true for the T.sub.1 as well.
[0107] The first peak value of the phosphorescence emission
spectrum of fluorene, which is the mother skeleton of the organic
compound of the present invention, in a low-temperature dilute
solution is 429 nm. In addition, each (divalent or more) aromatic
hydrocarbon group represented by Z.sub.2 is selected from skeletons
each having a first peak value of its phosphorescence emission
spectrum in a low-temperature dilute solution of less than 520 nm
and each having a high T.sub.1.
[0108] Thus, the organic compound of the present invention has a
high T.sub.1 and the first peak value of its phosphorescence
emission spectrum in a low-temperature dilute solution is
maintained at less than 520 nm. On the other hand, each of
Compounds C-1, C-2, and C-3 has a skeleton (a fluoranthene skeleton
or a benzofluoranthene skeleton) having a T.sub.1 lower than that
of the (divalent or more) aromatic hydrocarbon group represented by
Z.sub.2. Accordingly, the first peak value of the phosphorescence
emission spectrum of each of the compounds in a low-temperature
dilute solution is 520 nm or more. For example, the first peak
values of fluoranthene and benzofluoranthene are 540 nm and 566 nm,
respectively. For information, the T.sub.1 of Compound C-1 having a
fluoranthene skeleton is 557 nm.
[0109] Here, Table 4 below shows an absorption first peak
wavelength (first peak at longer wavelengths) in an absorption
spectrum in a toluene dilute solution and a phosphorescence
emission peak wavelength at 77 K in a toluene dilute solution.
TABLE-US-00004 TABLE 4 Absorption first peak T.sub.1 Compound
wavelength (nm) (nm) Exemplified 308 444 Compound AA-1 Exemplified
308 505 Compound AA-9 Exemplified 303 443 Compound AA-20 Compound
c-1 405 557 Compound c-11 336 435 Compound c-12 352 462 Compound
c-13 303 429 Compound c-21 362 540 Compound c-22 405 566 (Note 1)
The absorption first peak wavelength is defined from the peak
wavelength of the toluene solution (1 .times. 10.sup.-6 mol/l) at
the longest wavelength. It should be noted that a spectrophotometer
U-3010 manufactured by Hitachi, Ltd. is used in the measurement.
(Note 2) The toluene solution (1 .times. 10.sup.-4 mol/l) is cooled
to 77 K, its phosphorescence emission component is measured at an
excitation wavelength of 320 nm, and the peak wavelength at the
shortest wavelength is defined as the T.sub.1. It should be noted
that a spectrophotometer U-3010 manufactured by Hitachi, Ltd. is
used in the measurement.
[0110] By the way, the structure of the entire molecule of each of
the organic compounds represented by the general formulae [3] and
[4] is non-planar because the compound is bonded to an adjacent
substituent at the 4-position of its fluorene skeleton. When the
organic compound of the present invention is brought into a
thin-film state, the film becomes an amorphous film that hardly
crystallizes and is stable by virtue of the presence of the
foregoing feature. In addition, the presence of the feature can
suppress the occurrence of an excimer because the presence
suppresses the occurrence of intermolecular stacking.
[0111] By virtue of the foregoing features, the organic compound of
the present invention is useful as a constituent material for an
organic light-emitting device, specifically, a host to be
incorporated into its emission layer. In addition, the organic
compound of the present invention can provide an organic
light-emitting device having high device durability because an
amorphous film that hardly crystallizes and is stable can be formed
from the compound.
[0112] In addition, the compound has a wide band gap and a T.sub.1
of less than 520 nm. Accordingly, when the compound is used as a
host for a blue fluorescent light-emitting material or for a blue
or green phosphorescent light-emitting material out of the hosts,
light emission derived from a light-emitting dopant can be output.
Here, its features, i.e., a wide band gap and a T.sub.1 of less
than 520 nm exhibit a large suppressing effect on the diffusion of
an exciton from the emission layer, and hence the compound is also
useful as a transport layer such as a hole transport layer or an
electron transport layer, or a layer for blocking a charge such as
an electron-blocking layer or a hole-blocking layer.
[0113] Specific examples of the organic compound of the present
invention are listed below.
##STR00034## ##STR00035## ##STR00036## ##STR00037## ##STR00038##
##STR00039##
[0114] Of the listed compounds, Exemplified Compounds AA-1 to AA-4
are a group of compounds each corresponding to the organic compound
represented by the general formula [4]. Each of those compounds has
a high deposition speed at the time of its vacuum deposition
because of the following reason: the compound has a small molecular
weight, and hence has high sublimability and sublimates at a low
temperature.
[0115] Of the listed compounds, Exemplified Compounds AA-9 to AA-11
are a group of compounds each corresponding to the organic compound
represented by the general formula [3] and are a group of compounds
in each of which Z.sub.2 represents a naphthyl group or a fluorenyl
group. The T.sub.1's of the compounds themselves are high because
each of a naphthyl group and a fluorenyl group is a substituent
having a T.sub.1 of 500 nm or less. Accordingly, the use of any
such compound as a host to be incorporated into an emission layer
constituting an organic light-emitting device or as a constituent
material for a charge transport layer or charge-blocking layer may
improve its emission efficiency. The compounds are particularly
preferred in green phosphorescent light-emitting devices.
[0116] Of the listed compounds, Exemplified Compounds AA-17 to
AA-19 are a group of compounds each corresponding to the organic
compound represented by the general formula [3] and are a group of
compounds in each of which Z.sub.2 represents a carbon atom or an
aliphatic condensed polycyclic group. Each compound belonging to
the compound group is of such a structure that conjugation with a
fluorene skeleton does not occur. Accordingly, both of its band gap
and T.sub.1 enlarge. Therefore, the compound is preferred in a blue
phosphorescent device.
[0117] Of the listed compounds, Exemplified Compounds AA-20 to
AA-23 are a group of compounds each corresponding to the organic
compound represented by the general formula [3] and are a group of
compounds in each of which Z.sub.2 represents an oxygen atom. Each
compound belonging to the compound group has a low ionization
potential because the compound has an electron-donating effect
based on an oxygen atom. Accordingly, the use of the compound as a
host to be incorporated into an emission layer constituting an
organic light-emitting device or as a constituent material for a
hole transport layer or electron-blocking layer promotes the
injection of a hole and reduces its driving voltage.
[0118] Of the listed compounds, Exemplified Compounds AA-28 to
AA-35 are a group of compounds each corresponding to the organic
compound represented by the general formula [3] and are a group of
compounds in each of which Z.sub.2 represents an aromatic condensed
polycyclic group obtained by condensing three or more rings. Here,
the aromatic condensed polycyclic group obtained by condensing
three or more rings is a substituent having a T.sub.1 of 580 nm or
less and high planarity, specifically, a phenanthryl group or a
triphenylenyl group. Each compound belonging to the compound group
has a high T.sub.1, and hence its use as a host to be incorporated
into an emission layer constituting an organic light-emitting
device or as a constituent material for a hole transport layer or
electron-blocking layer may improve its emission efficiency. The
compound is particularly preferably used as a constituent material
for a green or red phosphorescent light-emitting device. In
addition, each compound belonging to the compound group has a
substituent having high planarity, and hence carrier hopping
between its molecules may be promoted and its carrier mobility may
be high.
[0119] The organic compound of the present invention, which is
mainly used as a constituent material for an organic light-emitting
device, can be used as a material not only for the organic
light-emitting device but also for a living organism internal
indicator or filter film.
[0120] When the organic compound of the present invention is used
as a constituent material for the organic light-emitting device,
embodiments of the organic light-emitting device including the
organic compound of the present invention are roughly classified
into two embodiments, specifically, the following embodiments (2A)
and (2B):
(2A) an organic light-emitting device including at least an anode,
a cathode, an emission layer formed between the anode and the
cathode, and an organic compound layer formed between the anode and
the emission layer, the organic compound layer containing a
compound having a tertiary amine structure; and (2B) an organic
light-emitting device including an anode, a cathode, and an organic
compound layer formed between the anode and the cathode.
[0121] When the organic compound of the present invention is used
as a constituent material for the organic light-emitting device
according to the aspect (2A), the organic compound of the present
invention is incorporated into the organic compound layer together
with the compound having a tertiary amine structure ("Compound B"
described in the section "(1) Organic light-emitting device").
Here, the organic compound layer constituting the organic
light-emitting device according to the aspect (2A) is a layer
formed between the anode and the emission layer. Accordingly, the
organic compound of the present invention is incorporated into a
layer formed between the anode and the emission layer such as a
hole transport layer, a hole injection layer, or an
electron-blocking layer.
[0122] By the way, the aspect (2B) can be subdivided into the
following (2B-1) to (2B-3):
(2B-1) an organic light-emitting device including an anode, a
cathode, an emission layer formed between the anode and the
cathode, and an organic compound layer (hole injection/transport
layer) formed between the anode and the emission layer; (2B-2) an
organic light-emitting device including an anode, a cathode, an
emission layer formed between the anode and the cathode, and an
organic compound layer (electron injection/transport layer) formed
between the cathode and the emission layer; and (2B-3) an organic
light-emitting device including an anode, a cathode, and an
emission layer formed between the anode and the cathode (an organic
light-emitting device including an emission layer as the "organic
compound layer" in the aspect (2B)).
[0123] When the organic compound of the present invention is used
as a constituent material for the organic light-emitting device
according to the aspect (2B), examples of the organic compound
layer containing the organic compound of the present invention
include an emission layer, a hole injection/transport layer (a hole
injection layer, a hole transport layer, or an electron-blocking
layer), and an electron injection/transport layer (an electron
injection layer, an electron transport layer, or a hole.cndot.
exciton-blocking layer). In addition, when the organic compound of
the present invention is used as a constituent material for the
organic light-emitting device according to the aspect (2B), the
layer containing the organic compound of the present invention may
be a single layer or may be multiple layers. Further, when the
organic compound of the present invention is used as a constituent
material for the organic light-emitting device according to the
aspect (2B), the layer containing the organic compound of the
present invention may be a layer formed only of the organic
compound of the present invention, or may be a layer obtained by
mixing the organic compound of the present invention and any other
compound.
[0124] The basic construction of the organic light-emitting device
including the organic compound of the present invention is, for
example, described in each of the following constructions (a) to
(e), provided that the present invention is not limited
thereto.
(a) (Substrate/) anode/emission layer/cathode (b) (Substrate/)
anode/hole transport layer/electron transport layer/cathode (c)
(Substrate/) anode/hole transport layer/emission layer/electron
transport layer/cathode (d) (Substrate/) anode/hole injection
layer/hole transport layer/emission layer/electron transport
layer/cathode (e) (Substrate/) anode/hole transport layer/emission
layer/hole.cndot. exciton-blocking layer/electron transport
layer/cathode
[0125] Although each of the constructions (a) to (e) is a
construction in the case where an electrode close to the substrate
is the anode, the present invention is not limited thereto and a
construction in the case where the electrode close to the substrate
is the cathode is of course included in the present invention.
(3) Other Constituent Materials for Organic Light-Emitting
Device
[0126] Next, other constituent materials for the organic
light-emitting device of the present invention (materials except
the compound A (including a compound corresponding to the organic
compound of the present invention) and the compound B) are
described. In the organic light-emitting device of the present
invention, conventionally known low-molecular weight and
high-molecular weight materials can be used as required. More
specifically, a hole injectable/transportable material, an emission
assist material, an electron injectable/transportable material, or
the like can be used.
[0127] Hereinafter, examples of these materials are described.
[0128] Examples of the hole injectable/transportable material
include a triarylamine derivative, a phenylenediamine derivative, a
stilbene derivative, a phthalocyanine derivative, a porphyrin
derivative, poly(vinyl carbazole), poly(thiophene), and any other
conductive polymer. It should be noted that the present invention
is not limited to these materials.
[0129] As a light-emitting material (guest) mainly involved in
light-emitting function, there are given, for example: a
fluorescent light-emitting material that emits blue, green, or red
light such as a triarylamine derivative, a phenylene derivative, a
condensed ring aromatic compound (e.g., a fluoranthene derivative,
a benzofluoranthene derivative, a pyrene derivative, a chrysene
derivative, or a derivative obtained by substitution thereof with a
diarylamine), or a stilbene derivative; and a phosphorescent
light-emitting material that emits blue, green, or red light such
as an organic metal complex (e.g., an organic iridium complex, an
organic platinum complex, or a rare earth metal complex).
[0130] In the present invention, the content of the guest is
preferably 0.1 mass % or more and 30 mass % or less, more
preferably 0.5 mass % or more and 10 mass % or less with reference
to the total amount of the emission layer.
[0131] The host in the emission layer is a material having the
highest weight ratio in the emission layer. Examples of the host
include, but of course not limited to, a triarylamine derivative, a
phenylene derivative, a condensed ring aromatic compound (e.g., a
naphthalene derivative, a phenanthrene derivative, a fluorene
derivative, or a chrysene derivative), an organic metal complex
(e.g., an organic aluminum complex such as
tris(8-quinolinolato)aluminum, an organic beryllium complex, an
organic iridium complex, or an organic platinum complex), and a
polymer derivative such as a poly(phenylene vinylene) derivative, a
poly(fluorene) derivative, a poly(phenylene) derivative, a
poly(thienylene vinylene) derivative, or a poly(acetylene)
derivative.
[0132] More specific examples of the host include the group of
compounds represented in Table 5.
TABLE-US-00005 TABLE 5 ##STR00040## H1 ##STR00041## H2 ##STR00042##
H3 ##STR00043## H4 ##STR00044## H5 ##STR00045## H6 ##STR00046## H7
##STR00047## H8 ##STR00048## H9 ##STR00049## H10 ##STR00050## H11
##STR00051## H12 ##STR00052## H13 ##STR00053## H14 ##STR00054## H15
##STR00055## H16 ##STR00056## H17 ##STR00057## H18 ##STR00058## H19
##STR00059## H20 ##STR00060## H21 ##STR00061## H22 ##STR00062## H23
##STR00063## H24
[0133] Examples of the host include, but of course not limited to:
condensed ring compounds (such as a fluorene derivative, a
naphthalene derivative, an anthracene derivative, a pyrene
derivative, a carbazole derivative, a quinoxaline derivative, and a
quinoline derivative); an organic aluminum complex such as
tris(8-quinolinolato)aluminum; an organic zinc complex; a
triphenylamine derivative; and polymer derivatives such as a
poly(fluorene) derivative and a poly(phenylene) derivative in
addition to the group of compounds represented in Table 5
above.
[0134] The electron injectable/transportable material can be
arbitrarily selected from materials that allow electrons to be
easily injected from the cathode and can transport the injected
electrons to the emission layer in consideration of, for example,
the balance with the hole mobility of the hole transportable
material. Examples of the material having electron-injecting
performance and electron-transporting performance include an
oxadiazole derivative, an oxazole derivative, a pyrazine
derivative, a triazole derivative, a triazine derivative, a
quinoline derivative, a quinoxaline derivative, a phenanthroline
derivative, and an organic aluminum complex.
[0135] A constituent material for the anode desirably has as large
a work function as possible. Examples thereof may include: metal
simple substances such as gold, platinum, silver, copper, nickel,
palladium, cobalt, selenium, vanadium, and tungsten or alloys
obtained by combining these metal simple substances; metal oxides
such as tin oxide, zinc oxide, indium oxide, indium tin oxide
(ITO), and indium zinc oxide; and conductive polymers such as
polyaniline, polypyrrole, and polythiophene.
[0136] One kind of those electrode substances may be used alone, or
two or more kinds thereof may be used in combination. In addition,
the anode may be of a single-layer construction or may be of a
multilayer construction.
[0137] On the other hand, a constituent material for the cathode
desirably has as small a work function as possible. Examples
thereof include: metal simple substances such as alkali metals such
as lithium; alkaline earth metals such as calcium; and aluminum,
titanium, manganese, silver, lead, and chromium. Alternatively,
alloys obtained by combining those metal simple substances can be
used. For example, a magnesium-silver alloy, an aluminum-lithium
alloy, or an aluminum-magnesium alloy can be used. A metal oxide
such as indium tin oxide (ITO) can also be utilized. One kind of
those electrode substances may be used alone, or two or more kinds
thereof may be used in combination. In addition, the cathode may be
of a single-layer construction or may be of a multilayer
construction.
[0138] The organic compound layer (such as the hole injection
layer, the hole transport layer, the electron-blocking layer, the
emission layer, the hole-blocking layer, the electron transport
layer, or the electron injection layer) for forming the organic
light-emitting device of the present invention is formed by the
following method.
[0139] A dry process such as a vacuum deposition method, an ionized
vapor deposition method, sputtering, or a plasma process can be
used for the formation of the organic compound layer for forming
the organic light-emitting device of the present invention. In
addition, a wet process involving dissolving the constituent
materials in an appropriate solvent and forming a layer by a known
application method (such as spin coating, dipping, a casting
method, an LB method, or an ink jet method) can be used instead of
the dry process.
[0140] Here, when the layer is formed by the vacuum deposition
method, the solution application method, or the like, the layer
hardly undergoes crystallization or the like and is excellent in
stability over time. In addition, when the layer is formed by the
application method, the film can be formed in combination with an
appropriate binder resin.
[0141] Examples of the binder resin include, but not limited to, a
polyvinyl carbazole resin, a polycarbonate resin, a polyester
resin, an ABS resin, an acrylic resin, a polyimide resin, a phenol
resin, an epoxy resin, a silicone resin, and a urea resin.
[0142] In addition, one kind of those binder resins may be used
alone as a homopolymer or a copolymer, or two or more kinds thereof
may be used as a mixture. Further, a known additive such as a
plasticizer, an antioxidant, or a UV absorber may be used in
combination as required.
(4) Application of Organic Light-Emitting Device
[0143] The organic light-emitting device of the present invention
can be used as a constituent member for a display apparatus or
lighting apparatus. In addition, the organic light-emitting device
finds use in applications such as an exposure light source for an
image-forming apparatus of an electrophotographic system, a
backlight for a liquid crystal display apparatus, and a
light-emitting apparatus including a white light source and a color
filter. Examples of the color filter include filters that transmit
light beams having three colors, i.e., red, green, and blue
colors.
[0144] A display apparatus of the present invention includes the
organic light-emitting device of the present invention in its
display portion. It should be noted that the display portion
includes multiple pixels.
[0145] In addition, the pixels each include the organic
light-emitting device of the present invention and a transistor as
an example of an active device (switching device) or amplifying
device for controlling emission luminance, and the anode or cathode
of the organic light-emitting device and the drain electrode or
source electrode of the transistor are electrically connected to
each other. Here, the display apparatus can be used as an image
display apparatus for a PC or the like. The transistor is, for
example, a TFT device and the TFT device is provided on, for
example, the insulating surface of a substrate. In addition, the
TFT device preferably includes an electrode formed of a transparent
oxide semiconductor.
[0146] The display apparatus may be an image information processing
apparatus that includes an image input portion for inputting image
information from, for example, an area CCD, a linear CCD, or a
memory card, and displays an input image on its display
portion.
[0147] In addition, the display portion of an imaging apparatus or
inkjet printer may have a touch panel function. The drive system of
the touch panel function is not particularly limited.
[0148] In addition, the display apparatus may be used in the
display portion of a multifunction printer.
[0149] A lighting apparatus is an apparatus for lighting, for
example, the inside of a room. The lighting apparatus may emit
light having any one of the following colors: a white color (having
a color temperature of 4,200 K), a daylight color (having a color
temperature of 5,000 K), and colors ranging from blue to red
colors.
[0150] A lighting apparatus of the present invention includes the
organic light-emitting device of the present invention and an AC/DC
converter circuit (circuit for converting an AC voltage into a DC
voltage) connected to the organic light-emitting device and
supplying a driving voltage to the organic light-emitting device.
It should be noted that the lighting apparatus may further include
a color filter.
[0151] An image-forming apparatus of the present invention is an
image-forming apparatus including: a photosensitive member; a
charging portion for charging the surface of the photosensitive
member; an exposure portion for exposing the photosensitive member
to form an electrostatic latent image; and a developing unit for
developing the electrostatic latent image formed on the surface of
the photosensitive member. Here, the exposing unit to be provided
in the image-forming apparatus includes the organic light-emitting
device of the present invention.
[0152] In addition, the organic light-emitting device of the
present invention can be used as a constituent member
(light-emitting member) for an exposing machine for exposing a
photosensitive member. An exposing machine including the organic
light-emitting device of the present invention is, for example, an
exposing machine in which a plurality of the organic light-emitting
devices of the present invention are placed to form a line along a
predetermined linear direction.
[0153] Next, the display apparatus of the present invention is
described with reference to the drawing. FIG. 1 is a schematic
sectional view illustrating an example of a display apparatus
including an organic light-emitting device and a switching device
connected to the organic light-emitting device. It should be noted
that the organic light-emitting device of the present invention is
used as the organic light-emitting device constituting a display
apparatus 1 of FIG. 1.
[0154] The display apparatus 1 of FIG. 1 includes a substrate 11
made of glass or the like and a moisture-proof film 12 for
protecting a TFT device 18 or organic compound layer as the
switching device, the film being formed on the substrate. In
addition, a metal gate electrode 13 is represented by reference
numeral 13, a gate insulating film 14 is represented by reference
numeral 14, and a semiconductor layer is represented by reference
numeral 15.
[0155] The TFT device 18 includes the semiconductor layer 15, a
drain electrode 16, and a source electrode 17. An insulating film
19 is formed on the TFT device 18. An anode 21 constituting the
organic light-emitting device and the source electrode 17 are
connected to each other through a contact hole 20.
[0156] It should be noted that a system for the electrical
connection between the electrode (anode or cathode) in the organic
light-emitting device and the electrode (source electrode or drain
electrode) in the TFT is not limited to the aspect illustrated in
FIG. 1. In other words, one of the anode and the cathode, and one
of the source electrode and drain electrode of the TFT device have
only to be electrically connected to each other.
[0157] Although multiple organic compound layers are illustrated
like one layer in the display apparatus 1 of FIG. 1, an organic
compound layer 22 may be multiple layers. A first protective layer
24 and second protective layer 25 for suppressing the deterioration
of the organic light-emitting device are formed on a cathode
23.
[0158] When the display apparatus 1 of FIG. 1 is a display
apparatus that emits white light, an emission layer in the organic
compound layer 22 in FIG. 1 may be a layer obtained by mixing a red
light-emitting material, a green light-emitting material, and a
blue light-emitting material. In addition, the layer may be a
laminated emission layer obtained by laminating a layer formed of
the red light-emitting material, a layer formed of the green
light-emitting material, and a layer formed of the blue
light-emitting material. Further, alternatively, the following
aspect is permitted: the layer formed of the red light-emitting
material, the layer formed of the green light-emitting material,
and the layer formed of the blue light-emitting material are, for
example, arranged side by side to form domains in one emission
layer.
[0159] Although the transistor is used as the switching device in
the display apparatus 1 of FIG. 1, an MIM device may be used
instead of the transistor as the switching device.
[0160] In addition, the transistor to be used in the display
apparatus 1 of FIG. 1 is not limited to a transistor using a
monocrystalline silicon wafer and may be a thin-film transistor
including an active layer on the insulating surface of a substrate.
A thin-film transistor using monocrystalline silicon as the active
layer, a thin-film transistor using non-monocrystalline silicon
such as amorphous silicon or microcrystalline silicon as the active
layer, or a thin-film transistor using a non-monocrystalline oxide
semiconductor such as an indium zinc oxide or an indium gallium
zinc oxide as the active layer is also permitted. It should be
noted that the thin-film transistor is also called a TFT
device.
[0161] The transistor in the display apparatus 1 of FIG. 1 may be
formed in a substrate such as an Si substrate. Here, the phrase
"formed in a substrate" means that the transistor is produced by
processing the substrate itself such as an Si substrate. In other
words, the presence of the transistor in the substrate can be
regarded as follows: the substrate and the transistor are
integrally formed.
[0162] Whether the transistor is provided in the substrate is
selected depending on definition. In the case of, for example, a
definition of about a QVGA per inch, the organic light-emitting
device is preferably provided in the Si substrate.
[0163] As described above, the driving of the display apparatus
using the organic light-emitting device of the present invention
enables display that has good image quality and is stable over a
long time period.
EXAMPLES
[0164] Hereinafter, the present invention is described in detail by
way of Examples, but the present invention is not limited to
Examples described below.
Example 1
Synthesis of Exemplified Compound AA-1
[0165] Exemplified Compound AA-1 was synthesized according to the
following synthesis scheme.
##STR00064##
[0166] The details of the synthesis scheme are described below.
(1) Synthesis of Compound b-3
[0167] The following reagents and solvents were loaded into a
100-ml three-necked flask.
Compound b-1: 10.3 g (34.3 mmol)
[0168] [1,1'-Bis(diphenylphosphino)propane]dichloronickel: 1.88 g
(3.43 mmol)
[0169] Compound b-2: 9.9 ml (68.5 mmol)
[0170] Toluene: 200 ml
[0171] Triethylamine: 30 ml
[0172] Next, in a nitrogen atmosphere, the temperature of the
reaction solution was increased to 90.degree. C. and then the
solution was stirred at the temperature (90.degree. C.) for 6
hours. After the completion of the reaction, 200 ml of water were
added to the resultant, and then an organic layer was extracted
with toluene and dried with anhydrous sodium sulfate. Next, a crude
product obtained by concentrating the organic layer under reduced
pressure was purified by silica gel column chromatography
(developing solvent: a mixed solvent of toluene and heptane) to
provide 12.2 g (yield: 82%) of Compound b-3 as a white crystal.
(2) Synthesis of Exemplified Compound AA-1
[0173] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0174] Compound b-1: 2.50 g (6.50 mmol)
[0175] Compound b-3: 3.65 g (8.43 mmol)
[0176] Cesium carbonate: 6.35 g
[0177] Toluene: 30 ml
[0178] Ethanol: 10 ml
[0179] Water: 30 ml
[0180] Next, in a nitrogen atmosphere, 376 mg of
tetrakis(triphenylphosphine)palladium(0) were added while the
reaction solution was stirred at room temperature. Next, the
temperature of the reaction solution was increased to 80.degree. C.
and then the solution was stirred at the temperature (80.degree.
C.) for 5 hours. After the completion of the reaction, an organic
layer was extracted with toluene and dried with anhydrous sodium
sulfate. Next, a crude product obtained by concentrating the
organic layer under reduced pressure was purified by silica gel
column chromatography (developing solvent: a mixed solvent of
toluene and heptane) to provide 3.70 g (yield: 93%) of Compound
AA-1 as a white crystal.
[0181] Mass spectrometry confirmed 611 as the M.sup.+ of
[0182] Exemplified Compound AA-1. In addition, .sup.1H-NMR
measurement confirmed the structure of Exemplified Compound
AA-1.
[0183] .sup.1H-NMR (CDCl.sub.3, 400 MHz) .sigma. (ppm): 7.51 (s,
2H), 7.34-7.33 (m, 4H), 6.86 (d, 2H), 6.36 (s, 2H), 1.56 (s, 6H),
1.52 (s, 6H), 1.41 (s, 18H), 1.27 (s, 18H)
Example 2
Synthesis of Exemplified Compound AA-6
[0184] Exemplified Compound AA-6 was synthesized according to the
following synthesis scheme.
##STR00065##
[0185] The details of the synthesis scheme are described below.
[0186] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0187] 1,4-Dibromo-2,3,5,6-tetrafluorobenzene: 1.0 g (3.3 mmol)
[0188] Compound b-3: 3.1 g (7.2 mmol)
[0189] Cesium carbonate: 9.3 g
[0190] Toluene: 30 ml
[0191] Ethanol: 15 ml
[0192] Water: 15 ml
[0193] Next, in a nitrogen atmosphere, 0.23 g of
tetrakis(triphenylphosphine)palladium(0) was added while the
reaction solution was stirred at room temperature. Next, the
temperature of the reaction solution was increased to 90.degree. C.
and then the solution was stirred at the temperature (90.degree.
C.) for 5 hours. After the completion of the reaction, an organic
layer was extracted with toluene and dried with anhydrous sodium
sulfate. Next, a crude product obtained by concentrating the
organic layer under reduced pressure was purified by silica gel
column chromatography (developing solvent: a mixed solvent of
toluene and heptane) to provide 1.9 g (yield: 77%) of Exemplified
Compound AA-6 as a white crystal.
[0194] Mass spectrometry confirmed 759 as the M.sup.+ of
[0195] Exemplified Compound AA-6.
Example 3
Synthesis of Exemplified Compound AA-8
[0196] Exemplified Compound AA-8 was synthesized according to the
following synthesis scheme.
##STR00066##
[0197] The details of the synthesis scheme are described below.
[0198] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0199] 1,3,5-Tribromobenzene: 0.630 g (2.00 mmol)
[0200] Compound b-3: 3.46 g (8.00 mmol)
[0201] Cesium carbonate: 7.0 g
[0202] Toluene: 30 ml
[0203] Ethanol: 10 ml
[0204] Water: 30 ml
[0205] Next, in a nitrogen atmosphere, 231 mg of
tetrakis(triphenylphosphine)palladium(0) were added while the
reaction solution was stirred at room temperature. Next, the
temperature of the reaction solution was increased to 80.degree. C.
and then the solution was stirred at the temperature (80.degree.
C.) for 5 hours. After the completion of the reaction, an organic
layer was extracted with toluene and dried with anhydrous sodium
sulfate. Next, a crude product obtained by concentrating the
organic layer under reduced pressure was purified by silica gel
column chromatography (developing solvent: a mixed solvent of
chloroform and heptane) to provide 0.85 g (yield: 43%) of
Exemplified
[0206] Compound AA-8 as a white crystal.
[0207] Mass spectrometry confirmed 991 as the M.sup.+ of
[0208] Exemplified Compound AA-8.
Example 4
Synthesis of Exemplified Compound AA-9
[0209] Exemplified Compound AA-9 was synthesized according to the
following synthesis scheme.
##STR00067##
[0210] The details of the synthesis scheme are described below.
[0211] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0212] 1,4-Dibromonaphthalene: 0.66 g (2.31 mmol)
[0213] Compound b-3: 2 g (4.62 mmol)
[0214] Cesium carbonate: 3.01 g
[0215] Toluene: 40 ml
[0216] Ethanol: 20 ml
[0217] Water: 7 ml
[0218] Next, in a nitrogen atmosphere, 267 mg of
tetrakis(triphenylphosphine)palladium(0) were added while the
reaction solution was stirred at room temperature. Next, the
temperature of the reaction solution was increased to 80.degree. C.
and then the solution was stirred at the temperature (80.degree.
C.) for 5 hours. After the completion of the reaction, an organic
layer was extracted with toluene and dried with anhydrous sodium
sulfate. Next, a crude product obtained by concentrating the
organic layer under reduced pressure was purified by silica gel
column chromatography (developing solvent: a mixed solvent of
toluene and heptane) to provide 1.65 g (yield: 97%) of Exemplified
Compound AA-9 as a white crystal.
[0219] Mass spectrometry confirmed 737 as the M.sup.+ of
Exemplified Compound AA-9. In addition, .sup.1H-NMR measurement
confirmed the structure of Exemplified Compound AA-9.
[0220] .sup.1H-NMR (CDCl.sub.3, 400 MHz) .sigma. (ppm): 7.70-7.67
(q, 2H), 7.63 (s, 2H), 7.54 (s, 2H), 7.42 (s, 2H), 7.37 (s, 2H),
7.32-7.28 (q, 2H), 6.90 (d, 2H), 6.48 (d, 2H), 1.61 (s, 6H), 1.59
(s, 6H), 1.44 (s, 18H), 1.30 (s, 18H)
Example 5
Synthesis of Exemplified Compound AA-7
[0221] Exemplified Compound AA-7 was synthesized according to the
following synthesis scheme.
##STR00068##
[0222] The details of the synthesis scheme are described below.
[0223] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0224] 1-tert-Butyl-3,5-dibromobenzene: 0.675 g (2.31 mmol)
[0225] Compound b-3: 2 g (4.62 mmol)
[0226] Cesium carbonate: 3.0 g
[0227] Toluene: 40 ml
[0228] Ethanol: 20 ml
[0229] Water: 7 ml
[0230] Next, in a nitrogen atmosphere, 267 mg of
tetrakis(triphenylphosphine)palladium(0) were added while the
reaction solution was stirred at room temperature. Next, the
temperature of the reaction solution was increased to 80.degree. C.
and then the solution was stirred at the temperature (80.degree.
C.) for 4 hours. After the completion of the reaction, an organic
layer was extracted with toluene and dried with anhydrous sodium
sulfate. Next, a crude product obtained by concentrating the
organic layer under reduced pressure was purified by silica gel
column chromatography (developing solvent: a mixed solvent of
chloroform and heptane) to provide 1.42 g (yield: 83%) of
Exemplified Compound AA-7 as a white crystal.
[0231] Mass spectrometry confirmed 743 as the M.sup.+ of
Exemplified Compound AA-7.
Example 6
Synthesis of Exemplified Compound AA-20
[0232] Exemplified Compound AA-20 was synthesized according to the
following synthesis scheme. It should be noted that tBu represents
a tert-butyl group.
##STR00069##
[0233] The details of the synthesis scheme are described below.
[0234] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0235] Compound b-1: 1.0 g (2.60 mmol)
[0236] Compound b-4: 0.11 g (0.26 mmol)
[0237] Potassium phosphate: 0.55 g
[0238] Dioxane: 10 ml
[0239] Water: 10 ml
[0240] Next, in a nitrogen atmosphere, 75 mg of palladium
dibenzylideneacetone were added while the reaction solution was
stirred at room temperature. Next, the temperature of the reaction
solution was increased to 80.degree. C. and then the solution was
stirred at the temperature (80.degree. C.) for 5 hours. After the
completion of the reaction, an organic layer was extracted with
toluene and dried with anhydrous sodium sulfate. Next, a crude
product obtained by concentrating the organic layer under reduced
pressure was purified by silica gel column chromatography
(developing solvent: a mixed solvent of chloroform and heptane) to
provide 33 mg of Exemplified Compound AA-20 as a white crystal.
[0241] Mass spectrometry confirmed 627 as the M.sup.+ of
Exemplified Compound AA-20. In addition, .sup.1H-NMR measurement
confirmed the structure of Exemplified Compound AA-20.
[0242] .sup.1H-NMR (CDCl.sub.3, 400 MHz) .sigma. (ppm): 8.04 (d,
2H), 7.44 (s, 2H), 7.28 (d, 2H), 7.16 (s, 2H), 6.94 (s, 2H), 1.56
(s, 6H), 1.54 (s, 6H), 1.37 (s, 18H), 1.27 (s, 18H)
Example 7
Synthesis of Exemplified Compound AA-2
##STR00070##
[0244] Exemplified Compound AA-2 was synthesized by the same method
as that of Example 1 except that: Compound b-10 was synthesized by
using Compound b-9 instead of Compound b-1 in the section (1) of
Example 1; and Compound b-9 was used instead of Compound b-1 and
Compound b-10 was used instead of Compound b-3 in the section (2)
of Example 1.
[0245] Mass spectrometry confirmed 923 as the M.sup.+ of
Exemplified Compound AA-2.
Example 8
Synthesis of Exemplified Compound AA-13
##STR00071##
[0247] Exemplified Compound AA-13 was synthesized by the same
method as that of Example 1 except that Compound b-11
(1,4-dibromonaphthalene) was used instead of Compound b-1 in the
section (2) of Example 1.
[0248] Mass spectrometry confirmed 763 as the M.sup.+ of
Exemplified Compound AA-13.
Example 9
Synthesis of Exemplified Compound AA-28
##STR00072##
[0250] Exemplified Compound AA-28 was synthesized by the same
method as that of Example 1 except that Compound b-12 was used
instead of Compound b-1 in the section (2) of Example 1.
[0251] Mass spectrometry confirmed 538 as the M.sup.+ of
Exemplified Compound AA-28.
Example 10
Synthesis of Exemplified Compound AA-35
##STR00073##
[0253] Exemplified Compound AA-35 was synthesized by the same
method as that of Example 1 except that Compound b-13
(1,3,5-tribromobenzene) was used instead of Compound b-1 in the
section (2) of Example 1.
[0254] Mass spectrometry confirmed 1,141 as the M.sup.+ of
Exemplified Compound AA-35.
[0255] Synthesis of Comparative Compound AZ-1
##STR00074##
[0256] Comparative Compound AZ-1 was synthesized by the same method
as that of Example 4 except that Compound b-32 was used instead of
1,4-dibromonaphthalene and Compound b-31 was used instead of
Compound b-3 in Example 4. Mass spectrometry confirmed 578 as the
M.sup.+ of Comparative Compound AZ-1.
Synthesis Example 1
Synthesis of Exemplified Compound AB-3
[0257] Exemplified Compound AB-3 was synthesized according to the
following synthesis scheme.
##STR00075##
[0258] The details of the synthesis scheme are described below.
[0259] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0260] 3,5-Dibromobenzene: 0.708 g (3.00 mmol)
[0261] Compound b-5: 2.71 g (7.00 mmol)
[0262] Cesium carbonate: 3.9 g
[0263] Toluene: 30 ml
[0264] Ethanol: 10 ml
[0265] Water: 30 ml
[0266] Next, in a nitrogen atmosphere, 173 mg of
tetrakis(triphenylphosphine)palladium(0) were added while the
reaction solution was stirred at room temperature. Next, the
temperature of the reaction solution was increased to 80.degree. C.
and then the solution was stirred at the temperature (80.degree.
C.) for 5 hours. After the completion of the reaction, an organic
layer was extracted with toluene and dried with anhydrous sodium
sulfate. Next, a crude product obtained by concentrating the
organic layer under reduced pressure was purified by silica gel
column chromatography (developing solvent: a mixed solvent of
chloroform and heptane) to provide 1.56 g (yield: 86%) of Compound
AB-3 as a white crystal.
[0267] Mass spectrometry confirmed 607 as the M.sup.+ of
Exemplified Compound AB-3.
Synthesis Example 2
Synthesis of Exemplified Compound AC-6
[0268] Exemplified Compound AC-6 was synthesized according to the
following synthesis scheme.
##STR00076##
[0269] The details of the synthesis scheme are described below.
(1) Synthesis of Compound b-6
[0270] The following reagents and solvent were loaded into a 100-ml
three-necked flask.
[0271] 2,6-Di-tert-butylnaphthalene: 1.0 g (4.17 mmol)
[0272] Bromine: 9.60 ml
[0273] Chloroform: 30 ml
[0274] Next, the temperature of the reaction solution was increased
to 65.degree. C. and then the solution was stirred at the
temperature (65.degree. C.) for 3.5 hours. After the completion of
the reaction, an organic layer was extracted with chloroform and
dried with anhydrous sodium sulfate. Next, the organic layer was
concentrated under reduced pressure and then 30 ml of methanol were
added to the concentrate to precipitate a crystal. The crystal was
filtered to provide 1.23 g (yield: 76%) of Compound b-6 as a white
crystal.
(2) Synthesis of Exemplified Compound AC-6
[0275] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0276] Compound b-6: 0.750 g (1.89 mmol)
[0277] Compound b-7: 1.80 g (3.16 mmol)
[0278] Cesium carbonate: 3.69 g
[0279] Toluene: 20 ml
[0280] Ethanol: 10 ml
[0281] Water: 20 ml
[0282] Next, in a nitrogen atmosphere, 109 mg of tetrakis
(triphenylphosphine) palladium(0) were added while the reaction
solution was stirred at room temperature. Next, the temperature of
the reaction solution was increased to 80.degree. C. and then the
solution was stirred at the temperature (80.degree. C.) for 5
hours. After the completion of the reaction, an organic layer was
extracted with toluene and dried with anhydrous sodium sulfate.
Next, a crude product obtained by concentrating the organic layer
under reduced pressure was purified by silica gel column
chromatography (developing solvent: a mixed solvent of chloroform
and heptane) to provide 0.75 g (yield: 65%) of Exemplified Compound
AC-6 as a white crystal.
[0283] Mass spectrometry confirmed 617 as the M.sup.+ of
Exemplified Compound AC-6. In addition, .sup.1H-NMR measurement
confirmed the structure of Exemplified Compound AC-6.
[0284] .sup.1H-NMR (CDCl.sub.3, 400 MHz) .sigma. (ppm): 7.88 (s,
2H), 7.55 (s, 2H), 7.49 (s, 2H), 7.42 (s, 2H), 7.41 (s, 2H), 1.41
(s, 36H), 1.33 (s, 18H)
Synthesis Example 3
Synthesis of Exemplified Compound AB-7
##STR00077##
[0286] Exemplified Compound AB-7 was synthesized by the same method
as that of Synthesis Example 1 except that Compound b-14 was used
instead of 1,3-dibromobenzene in Synthesis Example 1.
[0287] Mass spectrometry confirmed 683 as the M.sup.+ of
Exemplified Compound AB-7.
Synthesis Example 4
Synthesis of Exemplified Compound AB-6
[0288] Exemplified Compound AB-6 was synthesized according to the
following synthesis scheme.
##STR00078##
[0289] The details of the synthesis scheme are described below.
[0290] The following reagents and solvents were loaded into a
100-ml three-necked flask.
[0291] Compound b-15: 0.25 g (1.0 mmol)
[0292] Compound b-5: 1.0 g (2.60 mmol)
[0293] Compound b-4: 0.11 g (0.26 mmol)
[0294] Potassium phosphate: 0.55 g
[0295] Dioxane: 10 ml
[0296] Water: 10 ml
[0297] Next, in a nitrogen atmosphere, 75 mg of palladium
dibenzylideneacetone were added while the reaction solution was
stirred at room temperature. Next, the temperature of the reaction
solution was increased to 80.degree. C. and then the solution was
stirred at the temperature (80.degree. C.) for 5 hours. After the
completion of the reaction, an organic layer was extracted with
toluene and dried with anhydrous sodium sulfate. Next, a crude
product obtained by concentrating the organic layer under reduced
pressure was purified by silica gel column chromatography
(developing solvent: a mixed solvent of chloroform and heptane) to
provide 0.37 g (yield: 53%) of Exemplified Compound AB-6 as a white
crystal.
[0298] Mass spectrometry confirmed 707 as the M.sup.+ of
Exemplified Compound AB-6.
Example 11
[0299] In this example, an organic light-emitting device in which
an anode, a hole transport layer, an emission layer, a
hole-blocking layer, an electron transport layer, and a cathode
were formed in the stated order on a substrate was produced by a
method described below. Here, part of the compounds used in this
example are listed below.
##STR00079##
[0300] Indium tin oxide (ITO) was formed into a film on a glass
substrate by a sputtering method. Thus, the anode was formed. At
this time, the thickness of the anode was set to 120 nm. Next, the
substrate with the anode formed thereon was sequentially subjected
to ultrasonic washing with acetone and ultrasonic washing with
isopropyl alcohol (IPA), and was then subjected to boil washing
with IPA, followed by drying. Further, the dried product was
subjected to UV/ozone washing, and the resultant was used as a
transparent conductive supporting substrate in the following
steps.
[0301] Next, Exemplified Compound AC-6 (hereinafter referred to as
"compound A") and chloroform were mixed to prepare a material
solution A having a concentration of 0.25 wt %. In addition, BC-4
(hereinafter referred to as "compound B") and chloroform were mixed
to prepare a material solution B having a concentration of 0.25 wt
%.
[0302] Next, a mixed liquid was prepared by mixing the material
solution A and the material solution B so that their weight ratio
became 2:1.
[0303] Next, the mixed liquid was dropped onto the anode (ITO
electrode) and then a thin film was formed by spin coating at 500
RPM for 10 seconds and then at 1,000 RPM for 1 minute. After that,
the solvent in the thin film was completely removed by drying the
thin film in a vacuum oven at 80.degree. C. for 10 minutes. Thus,
the hole transport layer was formed. At this time, the thickness of
the hole transport layer was 30 nm.
[0304] Next, organic compound layers and electrode layers shown in
Table 6 below were continuously formed on the hole transport layer
by a vacuum deposition method involving using resistance heating in
a vacuum chamber at 1.times.10.sup.-5 Pa to produce the organic
light-emitting device.
TABLE-US-00006 TABLE 6 Constituent material Thickness [nm] Emission
layer c-2 (host) 20 c-1 (guest) (host:guest = 95:5 (weight ratio))
Hole-blocking layer c-3 10 Electron transport layer c-4 50 First
electrode layer LiF 0.5 (cathode) Second electrode layer Al 150
(cathode)
[0305] A current was passed through the resultant organic
light-emitting device, and then its emission characteristics when
its emission luminance was set to 2,000 cd/m.sup.2 were measured
and evaluated. As a result, the device had an emission efficiency
(cd/A) of 13.0 cd/A and an external quantum yield of 7.5%. In
addition, the device had CIE chromaticity coordinates of (0.16,
0.26) and was observed to emit blue light satisfactorily.
Examples 12 to 17
[0306] Organic light-emitting devices were each produced by the
same method as that of Example 11 except that the compound A and
the compound B were changed to compounds shown in Table 7 below in
Example 11. In addition, the resultant organic light-emitting
devices were evaluated by the same method as that of Example 11.
Table 7 shows the results.
Examples 18 to 20
[0307] Organic light-emitting devices were each produced by the
same method as that of Example 11 except that Exemplified Compound
AA-1 was used as the compound A and the compound B was changed to a
compound shown in Table 7 below in Example 11. In addition, the
resultant organic light-emitting devices were evaluated by the same
method as that of Example 11. Table 7 shows the results.
TABLE-US-00007 TABLE 7 External Com- Com- Emission quantum
Chromaticity pound pound efficiency yield coordinates A B [cd/A]
[%] [x, y] Example 11 AC-6 BC-4 13.0 7.5 (0.15, 0.26) Example 12
AA-1 BC-4 11.7 6.5 (0.16, 0.26) Example 13 AA-7 BC-4 11.3 6.3
(0.16, 0.26) Example 14 AA-9 BC-4 11.1 6.2 (0.15, 0.26) Example 15
AB-3 BC-4 12.3 6.9 (0.16, 0.25) Example 16 AB-7 BC-4 11.5 6.6
(0.15, 0.25) Example 17 AB-6 BC-4 12.1 6.8 (0.15, 0.25) Example 18
AA-1 BB-4 8.7 4.7 (0.16, 0.26) Example 19 AA-1 BF-1 8.9 5.0 (0.16,
0.26) Example 20 AA-1 BF-2 8.8 4.9 (0.16, 0.26)
Comparative Examples 1 to 3
[0308] Organic light-emitting devices were each produced by the
same method as that of Example 11 except that the compound A and
the compound B were changed to compounds shown in Table 8 below in
Example 11. In addition, the resultant organic light-emitting
devices were evaluated by the same method as that of Example 11.
Table 8 shows the results.
Comparative Example 4
[0309] An organic light-emitting device was produced by the same
method as that of Example 11 except that the hole transport layer
was formed using only the material solution B in Example 11. In
addition, the resultant organic light-emitting device was evaluated
by the same method as that of Example 11. Table 8 shows the
results.
Comparative Examples 5 to 7
[0310] Organic light-emitting devices were each produced by the
same method as that of Comparative Example 4 except that the
compound B was changed to a compound shown in Table 8 below in
Comparative Example 4. In addition, the resultant organic
light-emitting devices were evaluated by the same method as that of
Example 11. Table 8 shows the results.
TABLE-US-00008 TABLE 8 External Com- Com- Emission quantum
Chromaticity pound pound efficiency yield coordinates A B [cd/A]
[%] [x, y] Comparative AZ-1 BC-4 8.8 4.9 (0.16, 0.24) Example 1
Comparative AZ-2 BC-4 AZ-2 emitted light. Example 2 Comparative
AZ-3 BC-4 7.8 4.3 (0.15, 0.25) Example 3 Comparative -- BC-4 8.3
4.7 (0.15, 0.25) Example 4 Comparative -- BB-4 3.2 1.8 (0.15, 0.25)
Example 5 Comparative -- BF-1 2.4 1.3 (0.15, 0.25) Example 6
Comparative -- BF-2 2.2 1.2 (0.15, 0.25) Example 7
Example 21
[0311] In this example, an organic light-emitting device was
produced. An organic light-emitting device in which an anode, a
hole transport layer, an emission layer, a hole-blocking layer, an
electron transport layer, and a cathode were formed in the stated
order on a substrate was produced by a method described below.
Here, part of the compounds used in this example are listed
below.
##STR00080##
[0312] First, a transparent conductive supporting substrate was
produced by the same method as that of Example 11.
[0313] Next, a chloroform solution having a concentration of 0.25
wt % was prepared by mixing Exemplified Compound AA-1 and
chloroform. Next, the chloroform solution was dropped onto the
anode (ITO electrode) and then a thin film was formed by spin
coating at 500 RPM for 10 seconds and then at 1,000 RPM for 1
minute. After that, the solvent in the thin film was completely
removed by drying the thin film in a vacuum oven at 80.degree. C.
for 10 minutes. Thus, the hole transport layer was formed. At this
time, the thickness of the hole transport layer was 30 nm.
[0314] Next, organic compound layers and electrode layers shown in
Table 9 below were continuously formed on the hole transport layer
by a vacuum deposition method involving using resistance heating in
a vacuum chamber at 1.times.10.sup.-5 Pa to produce the organic
light-emitting device.
TABLE-US-00009 TABLE 9 Constituent material Thickness [nm] Emission
layer c-5 (host) 20 c-1 (guest) (host:guest = 95:5 (weight ratio))
Hole-blocking layer c-6 40 Electron transport layer c-7 40 First
electrode layer LiF 0.5 (cathode) Second electrode layer Al 150
(cathode)
[0315] A current was passed through the resultant organic
light-emitting device, and then its emission characteristics when
its emission luminance was set to 2,000 cd/m.sup.2 were measured
and evaluated. As a result, the device had an emission efficiency
(cd/A) of 7.2 cd/A and was observed to emit blue light
satisfactorily.
Example 22
[0316] An organic light-emitting device was produced by the same
method as that of Example 21 except that Exemplified Compound AA-20
was used instead of Exemplified Compound AA-1 in Example 21. The
emission characteristics of the organic light-emitting device were
measured and evaluated by the same method as that of Example 21. As
a result, the device had an emission efficiency (cd/A) of 8.0 cd/A
and was observed to emit blue light satisfactorily.
Example 23
[0317] An organic light-emitting device was produced by the same
method as that of Example 21 except that Exemplified Compound AA-35
was used instead of Exemplified Compound AA-1 in Example 21. The
emission characteristics of the organic light-emitting device were
measured and evaluated by the same method as that of Example 21. As
a result, the device had an emission efficiency (cd/A) of 7.1 cd/A
and was observed to emit blue light satisfactorily.
Example 24
[0318] Part of the compounds used in this example are listed
below.
##STR00081## ##STR00082##
[0319] Indium tin oxide (ITO) was formed into a film on a glass
substrate by a sputtering method. Thus, an anode was formed. At
this time, the thickness of the anode was set to 120 nm. Next, the
substrate with the anode formed thereon was sequentially subjected
to ultrasonic washing with acetone and ultrasonic washing with
isopropyl alcohol (IPA), and was then subjected to boil washing
with IPA, followed by drying. Further, the dried product was
subjected to UV/ozone washing, and the resultant was used as a
transparent conductive supporting substrate in the following
steps.
[0320] Next, organic compound layers and electrode layers shown in
Table 10 below were continuously formed by a vacuum deposition
method involving using resistance heating in a vacuum chamber at
1.times.10.sup.-5 Pa to produce an organic light-emitting
device.
TABLE-US-00010 TABLE 10 Constituent material Thickness [nm] Hole
injection layer d-1 40 Hole transport layer d-2 10 Emission layer
Exemplified Compound 30 AA-1 (host) d-3 (guest) (host:guest = 95:5
(weight ratio)) Hole-blocking layer d-4 10 Electron transport layer
d-5 30 First electrode layer LiF 0.5 (cathode) Second electrode
layer Al 150 (cathode)
[0321] A predetermined voltage was applied to the resultant organic
light-emitting device while its ITO electrode was defined as a
positive electrode and its Al electrode was defined as a negative
electrode. As a result, the device was observed to emit blue light
having CIE chromaticity coordinates of (0.21, 0.48).
Example 25
[0322] An organic light-emitting device was produced by the same
method as that of Example 24 except that Exemplified Compound AA-20
was used instead of Exemplified Compound AA-1 in Example 24. The
emission characteristics of the organic light-emitting device were
measured and evaluated by the same method as that of Example 24. As
a result, the device was observed to emit blue light having CIE
chromaticity coordinates of (0.21, 0.48).
[0323] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0324] This application claims the benefit of Japanese Patent
Application No. 2013-077439, filed Apr. 3, 2013, and Japanese
Patent Application No. 2014-076287, filed Apr. 2, 2014, which are
hereby incorporated by reference herein in their entirety.
REFERENCE SIGNS LIST
[0325] 17: TFT device, 20: anode, 21: organic compound layer, 22:
cathode
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